Evaluation of cytotoxic effects of fipronil on ovaries of semi-engorged Rhipicephalus sanguineus (Latreille, 1806) (Acari : Ixodidae) tick female

The ovary of the Rhipicephalus sanguineus dog tick female is structurally formed by oocytes in five different stages of development (from I to V) and attached to the gonad by the pedicel. The present study evaluated possible toxic effects of the acaricide fipronil (Frontline (R)) on ovaries of semi-engorged ticks. Sixty partially fed females of R. sanguineus tick were distributed into four groups of 15 specimens each: I - non-treated; II, III and IV - treated with 1, 5 and 10 ppm of fipronil, respectively. The acaricide induced structural changes in the oocytes of individuals of the different treated groups ranging from the presence of a few small vacuoles to cellular death. In conclusion, germinative cells of semi-engorged R. sanguineus tick female are affected by different concentrations of fipronil leading to the reduction of tick fertility. (c) 2008 Elsevier Ltd. All rights reserved.

Water quality index as a simple indicator of aquaculture effects on aquatic bodies

This paper proposes a water quality index (WQI) to subsidize management actions in the Medio Paranapanema Watershed in São Paulo State, Brazil, as a simple pollution indicator for aquaculture activity. Water quality of the Macuco and Queixada rivers was investigated for 2 years (from May 2003 to May 2005). The index proposed in this work is composed of three measurable environmental parameters-turbidity, total phosphorus and dissolved oxygen. Concentrations of these three variables were normalized on a scale from 0 to 100 and translated into statements of water quality (excellent, good, regular, fair and poor). The index was applied to seventeen monitoring points in the aquatic bodies described above and compared to others, one being that used by the Environmental Protection Agency of United States and proposed for the National Sanitation Foundation, other employing minimal index and the last one considering the minimum operator concept. The results show that the degradation in this watershed from aquaculture activity can be easily inferred with this index, which is more restricted than the others routinely used to infer water quality. (C) 2007 Elsevier Ltd. All rights reserved.

Efficacy of Endodontic Treatment for Endotoxin Reduction in Primarily Infected Root Canals and Evaluation of Cytotoxic Effects

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Consistent modified gravity: dark energy, acceleration and the absence of cosmic doomsday

We discuss modified gravity which includes negative and positive powers of curvature and provides gravitational dark energy. It is shown that in GR plus a term containing a negative power of curvature, cosmic speed-up may be achieved while the effective phantom phase (with w less than -1) follows when such a term contains a fractional positive power of curvature. Minimal coupling with matter makes the situation more interesting: even 1/R theory coupled with the usual ideal fluid may describe the (effective phantom) dark energy. The account of the R(2) term (consistent modified gravity) may help to escape cosmic doomsday.

Relevance of Electronic Effects on the Yield of CO2 from Methanol Oxidation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of matrix effects on the quantification of abscisic acid and its metabolites in the leaves of Bauhinia variegata L. using liquid chromatography combined with tandem mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fighting by sleep-deprived rats as a possible manifestation of panic: effects of sodium lactate

Increased fighting is an effect of desynchronized sleep deprivation (DSD) in rats, and recently this behavior has been suggested to be spontaneous panic and equivalent to panic disorder. In the present study we tested this hypothesis by evaluating the effect of sodium lactate on this aggressiveness, because this substance is recognized to induce spontaneous panic attacks in patients. A total of 186 male albino Wistar rats, 250-350 g, 90-120 days of age, were submitted to DSD (multiple platform method) for 0, 4, or 5 days. At the end of the deprivation period the rats were divided into subgroups respectively injected intraperitoneally with 1.86, 2.98 and 3.72 g/kg of 1 M sodium lactate, or 1.86 and 3.72 g/kg of 2 M sodium lactate. The control animals were submitted to the same procedures but received equivalent injections of sodium chloride. Regardless of DSD time, sleep-deprived animals that received sodium lactate presented a significantly higher mean number of fights (0.13 ± 0.02 fights/min) and a longer mean time spent in confrontation (2.43 ± 0.66 s/min) than the controls (0.01 ± 0.006 fights/min and 0.12 ± 0.07 s/min, respectively; P<0.01, Student t-test). For the sodium lactate group, concentration of the solution and time of deprivation increased the number of fights, with the mean number of fights and mean duration of fighting episodes being greater with the 2.98 g/kg dose using 1 M lactate concentration. These results support the hypothesis that fighting induced by DSD is probably a spontaneous panic manifestation. However, additional investigations are necessary in order to accept this as a promising animal model for studies on panic disorder.

Modified E-test by the addition of EDTA-Tris and dimethyl sulfoxide on the potentiation of the effects of some antimicrobials in Pseudomonas aeruginosa strains isolated from bovine mastitis

A concentração inibitória mínima-MIC em 30 estirpes de Pseudomonas aeruginosa isoladas de mastite bovina foi avaliada utilizando o E-test padrão e o método modificado, pela adição de Tris-EDTA e DMSO. Os métodos modificados apresentaram redução significativa da MIC das estirpes utilizando a gentamicina, a ciprofloxacina e a norfloxacina.

Avaliação da mutagenicidade e antimutagenicidade de um biopolímero extraído do microorganismo Agrobacterium radiobacter em camundongos Swiss

A presente pesquisa avaliou a ação mutagênica e antimutagênica de um biopolímero de glucose extraído da Agrobacterium radiobacter (Biopolímero de Agrobacterium radiobacter). O experimento foi realizado com camundongos Swiss machos divididos em oito grupos. O tratamento com o biopolímero foi realizado por gavage em dose única concomitante a uma dose de solução tampão fosfato nos grupos de avaliação da mutagenicidade, ou ao agente indutor de danos no DNA, ciclofosfamida, na concentração de 50 mg/kg (peso corpóreo - p.c.), nos grupos de avaliação da antimutagenicidade. Utilizou-se o teste de micronúcleo em sangue periférico e a coleta de sangue foi realizada 24 e 48 h após a aplicação das substâncias-teste. A análise estatística demonstrou que o biopolímero não possui atividade mutagênica e que é efetivo em prevenir danos no DNA. As porcentagens de redução de danos nos grupos de antimutagenicidade foram de 83,9%, 89,1% e 103,1% em 24 h e 101,24%, 98,14% e 120,64% em 48 h para as doses de 75, 150 e 300mg/kg (p.c.), respectivamente. A alta porcentagem de redução de danos associada à ausência de efeitos mutagênicos indica, além da atividade quimioprotetora, a possibilidade do biopolímero ser um alimento funcional candidato à utilização como co-adjuvante na quimioterapia para prevenir efeitos colaterais.

Determination of brilliant blue FCF in the presence and absence of erythrosine and quinoline yellow food colours by cathodic stripping voltammetry

A study of the voltammetric behaviour of the food colours brilliant blue FCF (C.I. 42090), erythrosine (C. I. 45430) and quinolin e yellow (C. I. 47005) in the pH range 2-10 have been carried out by cathodic stripping voltammetry. At pH 4.5 (acetate buffer) with an accumulation potential of 0 V and accumulation time of 30 s, the voltammograms presented well-defined reduction peaks at potential - 0.76 V for brilliant blue FCF, - 0.85 V for quinoline yellow and - 0.54 V for erythrosine. Linear calibration graphs were obtained from 8 to 80 mug l(-1) brilliant blue, from 4 to 43 mug l(-1) quinoline yellow and from 10 to 70 mug l(-1) erythrosine. The method has been successfully applied to identify and quantify binary mixtures of these dyes and applied for determining brilliant blue FCF in commercial food products.

Absence of promoting potential of bracken fern (Pteridium aquilinum) in rat urinary bladder carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine and uracil

Conventional studies on bracken fern (Pteridium aquilinum; PA) carcinogenicity have used high dietary concentrations (around 30%) and long-term exposure (up to 52-70 weeks) without consideration of the multistep character of the chemical carcinogenesis process. The present study evaluated specifically the promoting potential of 3-5% dietary crude PA in the rat urinary bladder mucosa in a 32-week-long initiation-promotion assay for chemical carcinogenesis. Initiation of urothelial carcinogenesis was accomplished with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Uracil (U) was provided through the diet in order to expand the population of initiated cells. Seven groups (C) of male Wistar rats were submitted to the following treatments: G1 = BBN (n = 8); G2 = U (n = 10); G3 = BBN-U (n = 9); G4 = BBN-PA-U-PA (n = 16); G5 = PA (n = 8); G6 = BBN-PA (n = 10); G7 = PA-U-PA (n = 12). At the end of the experiment rats presenting epithelial papillary or nodular hyperplasia (PNH), papillomas (PAP), or simultaneous PNH plus PAP numbered, respectively G1: 2-0-1; G2: 0-0-0; G3: 3-0-2; G4: 4-3-2; G5: 1-0-1; G6: 8-0-0; and G7: 0-0-0, with no significant differences in the incidence of lesions among the groups. More frequent and more severe lesions occurred in BBN-initiated animals, predominantly in those also exposed to uracil (G3 and G4). Low-dose crude bracken fern in the diet does not promote rat urinary bladder carcinogenesis after a 32-week period of exposure, even when the initiated urothelial cell population has been expanded through a mechanical stimulus. (C) 1995 Wiley-Liss, Inc.