Determination of the highest no-effect dose (HNED) and of the elimination pattern for cocaine in horses

Cocaine is one of the most widespread illegal stimulants utilized by the human population throughout the world. The aim of this study was to establish the highest no-effect dose (HNED) of cocaine on the spontaneous locomotor activity (SLA) of horses in a behavior chamber, and thereby to determine the maximal acceptable threshold of the urinary drug concentration in horses. Twelve English thoroughbred mares received 0.02, 0.03, 0.04, 0.08 or 0.12 mg kg(-1) cocaine i.v. or saline solution (control). It was noted that doses above 0.04 mg kg(-1) induced a significant increase in SLA (P < 0.05, Tukey's test). No significant increase in SLA was seen in the mares that received 0.03 mg kg(-1), but the animals showed important behavioral changes that did not occur after the 0.02 mg kg(-1) dose. It was concluded that the HNED of cocaine for horses in a behavior chamber is 0.02 mg kg(-1). After injection of this dose in five horses, urine samples were collected at predetermined intervals through vesical catheterization. The concentrations of cocaine, norcocaine, benzoylecgonine and ecgonine methyl ester were quantified by liquid chromatography/electrospray ionization tandem mass spectrometry. Cocaine and norcocaine concentrations remained consistently below the level of detection. Benzoylecgonine reached a mean (+/- SEM) maximum concentration of 531.9 +/- 168.7 ng ml(-1) after 4 h, whereas ecgonine methyl ester peaked 2 h after injection at a concentration of 97.2 +/- 26.5 ng ml(-1). The maximum admissible concentration for cocaine and/or metabolites in the urine of horses is difficult to establish unequivocally because of the substantial individual variation in the drug elimination pattern observed in horses, which can be inferred by the large standard error of the means obtained. Copyright (C) 2002 John Wiley Sons, Ltd.

Effects of caffeine on locomotor activity of horses: Determination of the no-effect threshold

Caffeine is the legal stimulant consumed most extensively by the human world population and may be found eventually in the urine and/or blood of race horses, the fact that caffeine is in foods led us to determine the highest no-effect dose (HNED) of caffeine on the spontaneous locomotor activity of horses and then to quantify this substance in urine until it disappeared. We built two behavioural stalls equipped with juxtaposed photoelectric sensors that emit infrared beams that divide the stall into nine sectors in a 'tic-tac-toe' fashion. Each time a beam was interrupted by a leg of the horse, a pulse was generated; the pulses were counted at 5-min intervals and stored by a microcomputer. Environmental effects were minimized by installing exhaust fans producing white noise that obscured outside sounds. One-way observation windows prevented the animals from seeing outside. The sensors were turned on 45 min before drug administration (saline control or caffeine), the animals were observed for up to 8 h after i.v. administration of 2.0, 2.5, 3.0 or 5.0 mg caffeine kg(-1). The HNED of caffeine for stimulation of the spontaneous locomotor activity of horses was 2.0 mg kg(-1). The quantification of caffeine in urine and plasma samples was done by gradient HPLC with UV detection. The no-effect threshold should not be greater than 2.0 mug caffeine ml(-1) plasma or 5.0 mug caffeine ml(-1) urine. Copyright (C) 2001 John Wiley & Sons, Ltd.

Respostas hematológicas em tuvira após anestesia com diferentes concentrações de óleo de cravo

The hematological responses in tuvira (Gymnotus aff. inaequilabiatus) after clove oil anesthesia at different concentrations were evaluated in this study. Fish (n = 25) with average length of 26.8 +/- 2.4 cm and weighing 94.4 +/- 23.6 g were separated in five groups composed with five animals each and submitted individually to respective concentrations of clove oil: 40, 80, 120, 160 and 200 mg L-1. After anesthetic recuperation, the blood samples collection were performed, as well as complete hemogram. The results were submitted to analysis of variance, Tukey test (P<0.05) and Sperman's correlation analysis. There was an increase (P<0.05) on hematocrit, red blood cells count, thrombocytes count and in the values of neutrophils with increasing of clove oil concentrations. In addition, positive correlation (P<0.05) were observed on total leukocytes, as well as negative linear correlation (P<0.05) for mean corpuscular hemoglobin concentration (MCHC). The clove oil anesthesia on tuvira cause hematological changes with an effect dose-dependent. These changes should be considered mainly in future studies designed to establish the reference values of hematologic variables for this specie.

Efeito da deriva de Glyphosate sobre algumas características fisiológicas em plantas de eucalipto

This work aims to evaluate the effects of a simulated drift of glyphosate at different doses on some physiological characteristics of Eucalyptus grandis. A completely randomized design with five replications was used, where each pot contained an eucalyptus plant and was considered as one repetition. The plants received doses of glyphosate corresponding to 0, 30, 60, 90 and 120g.ha(-1), in the Scout (R) commercial formulation: The application was performed in three forms: leaves, stem and whole plant (leaf + stem). For foliar application, the stem was covered with plastic tape to avoid being hit by the solution, and leaves with a plastic bag when the stem was spayed. The application was performed by means of a steady spray gun equipped with four XR 11002 tips, with a pressure of 200Kpa and a volume of 2001 ha(-1). Stomatal conductance, transpiration and leaf temperature were measured at 7 days after application (DAA). The eucalypt plants receiving applications in leaves and whole plant showed, at the highest glyphosate dosis (120g.ha(-1)), a transpiration reduced by 22% and an 18% increase of stomatal resistance at 7 DAA. The lowest dose (30g-ha(-1)) applied to the whole plant caused a transpiration stimulation of 18%, and a leaf to air difference in temperature of -1.66 degrees C, while the difference between the highest and lowest dose used was 3.5 degrees C.

In vitro cytotoxicity and in vivo-biocompatibility of contemporary resin-modified glass-ionomer cements

Objectives. To evaluate the effects of current resin-modified glass-ionomer cements (RMGICs) applied on culture of cells or implanted into subcutaneous tissue of rats.Methods. Experiment 1 - Thirty round-shaped samples of every RMGICs: Rely X Luting Cement (RL), Vitremer (VM), and Vitrebond (VB) were placed into wells with 1.1 mL of culture medium (DMEM), and incubated for 24,48 or 72 h. The extracts from every sample were applied on the MDPC-23 cells. Fresh DMEM was used as control group. The MTT assay was carried out for mitochondrial respiration. Experiment 2 - Fifty-four polyethylene tubes filled with the experimental materials were implanted into the dorsal subcutaneous tissue of rats. At 7, 30, and 90 days the animals were killed and the biopsies were processed for histological evaluation.Results. Experiment 1 - Both time of elution and material significantly influenced cell respiratory activity. in general, the extracts obtained at 24 h were less cytotoxic than 48 and 72 h incubation. The cytotoxic effect of VM and RL were not statistically different (P < 0.05) for the 24-hour period. VB showed the highest cytotoxic effect. Experiment 2 - All RMGICs elicited at 7 days a moderate to intense inflammatory reaction which decreased over time. However, connective healing occurred for most of samples at 90-day evaluation.Significance. Glass-ionomer cements may cause noticeable inflammatory response when in direct contact to connective tissue. The toxic effects of this kind of soluble material depend on the amount of components released in the aqueous environment. (C) 2005 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Nutrição e produtividade da nogueira-macadâmia em função de doses de nitrogênio

The objective of this work was to evaluate the influence of nitrogen doses on mineral nutrition and yield of macadamia nut (Macadamia integrifolia). The experiment was carried out during three agricultural years, in Jaboticabal, SP, Brazil. The experimental design was a complete block with four replicates. Five doses of N (0, 50, 100, 150, and 200 kg ha-1 per year), applied as urea, were evaluated. The increase in N doses increased the nutrient concentration in the leaves and the yield of nuts and almonds. Ca, Mg, and S contents decreased and the ones of Fe and Mg increased linearly with N fertilization. Nut and almond yields were positively correlated with leaf N concentration, and the range from 14 to 18 g kg-1 allowed the highest yields. The dose of 150 kg ha-1 of N per year provides higher nut yields, without reducing the recovery rate of almonds.

Caracterização agronômica e morfológica de populações de milho

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Chemical reduction of carboxyl groups in heparin abolishes its vasodilatory activity

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

Ação de enxaguatórios clareadores e sua associação ao clareamento caseiro com peróxido de carbamida

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of Aloe vera extract on the improvement of the respiratory activity of leukocytes of matrinxã during the transport stress

This study evaluated the effect of extract of Aloe vera in the transport water of matrinxã (Brycon amazonicus) fish on stress response and leukocyte respiratory activity. Fish was transported for 4 h in water containing Aloe at levels 0; 0.02; 0.2 and 2 mg/L, and sampled before transport 2, 4, 24 and 96 h after for determination of plasma glucose and respiratory activity of leukocytes. An additional in vitro assay was conducted with another fish species, pacu (Piaractus mesopotamicus), to test the respiratory burst of leukocytes exposed to Aloe extract (0.0, phosphate-buffered saline (PBS) only) at 0.1, 0.2, 0.5 and 1 mg/L). Plasma glucose increased after 2 and 4 h of transport and returned to control levels within 24 h, but the addition of Aloe in the transport water did not affect the level of blood glucose. However, at 2 h of transport, Aloe enhanced the respiratory activity of leukocytes in a dose-dependent way. The highest value of respiratory burst activity of leukocytes was observed in the fish transported in water containing Aloe at 2 mg/L. The enhancing effect of the plant extract on the production of oxygen radicals was confirmed in vitro in leukocytes of pacu incubated in Aloe at concentrations 0.1 and 0.2 mg/L. The results suggest that Aloe vera is a modulator of the immune system in fish improving the innate immune response tested.

Effect of liming on the mineral nutrition and yield of growing guava trees in a typic hapludox soil

High soil acidity influences the availability of mineral nutrients and increases that of toxic aluminium (Al), which has a jeopardizing effect on plant growth. The objective of this research was to evaluate the effects of soil liming on the development of guava (Psidium guajava L.) plants, on soil chemical characteristics, and on fruit yield. The experiment was carried out at the Bebedouro Citrus Experimental Station, state of São Paulo, Brazil, in a Typic Hapludox soil, from August 1999 to March 2003. The treatments consisted of limestone dose: D0 = zero; D1 = half dose; D2 = total dose; D3 = 1.5 times the dose, and D4 = 2 times the dose to raise the V value to 70%. The doses corresponded to zero, 1.85, 3.71, 5.56, and 7.41tha(-1) applied to the upper soil layer (0-30cm deep) before planting. The results showed that liming caused an improvement in the evaluated soil chemical characteristics up to a depth of 60cm in soil samples both in the line and between lines. The highest fruit yields were obtained when the base saturation reached a value of 55% in the line and 62% between the lines. Foliar levels of calcium (Ca) and magnesium (Mg) were 8.8 and 2.5gkg-1, respectively. The highest limestone dose maintained the soil base saturation (at the layer of 0-20cm) in the line close to 55% during at least 40 months after the incorporation of limestone.

Dose-dependent effect of Resveratrol on bladder cancer cells: Chemoprevention and oxidative stress

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

Effect of high-dose fentanyl on renal function in dogs

OBJETIVOS: Estudamos os efeitos de alta dose de fentanil (F) em atributos de função renal (FR) do cão. DESENHO: Anestesiamos com pentobarbital sódico (PS) 16 cães divididos aleatoriamente em 2 grupos: manutenção com PS (Gi) e PS com F (0,05 mg.kg-1) (G2). INTERVENÇÃO: os cães foram ventilados artificialmente e tiveram cateterizadas as veias femorais esquerda e direita e a artéria femoral esquerda para infusão de drogas e coleta de dados hemodinâmicos e de sangue para dosagens laboratoriais. Coletou-se urina durante todo experimento. MENSURAÇÃO: Determinaram-se os valores de atributos de FR.. RESULTADOS: PS não mudou a FR e o comportamento de G1 deveu-se à expansão do volume extracelular. O F diminuiu significativamente freqüência cardíaca, pressão arterial média, clearance de creatinina, volume urinário, clearance osmolar e excreção fracionária de sódio e potássio. CONCLUSÕES: A diminuição da FR foi provavelmente devida às alterações hemodinâmicas induzidas pelo F, não se descartando possível ação da aldosterona.

Effect of indomethacin on the pregnant rat

O objetivo deste trabalho foi avaliar a performance reprodutiva, estudo morfológico do fígado e característicapost mortem de ratas Wistar prenhes tratadas com indometacina, um inibidor geral de COX. Indometacina foi administrada oralmente, nas doses de 0 (controle), 0,32, 1,68 e 8,40 mg/kg/dia (n=10/grupo), nos dias 3 e 4 de prenhez (dia 0 = primeiro dia de prenhez = esperma positivo). Os animais foram eutanasiados sob anestesia no 11º dia de prenhez, e foram realizadas necropsia e cultura de microorganismos. Os resultados mostraram que as doses de 0,32 e 1,68 mg/kg de peso corpóreo (dose terapêutica para humanos) de indometacina não causaram efeitos embriotóxicos ou letais. A maior dose (8,40 mg/kg) de indometacina prejudicou o processo de implantação e, portanto, interferiu no desenvolvimento fetal. A peritonite foi detectada na necropsia e nos estudos bacteriológicos dos animais tratados com 8,4 mg/kg e considerada a causa-morte destes animais. Portanto, este estudo analisou um agente farmacológico na prenhez de roedores e evidenciou que a indometacina apresentou efeitos embriotóxicos e letais na maior dose empregada, mas foi segura na dose terapêutica usada pelo homem.

In vitro effect of low-level laser on odontoblast-like cells

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