The cuticular hydrocarbons profiles in the stingless bee Melipona marginata reflect task-related differences

Members of social insect colonies employ a large variety of chemical signals during their life. Of these, cuticular hydrocarbons are of primary importance for social insects since they allow for the recognition of conspecifics, nestmates and even members of different castes. The objectives of this study were (1) to characterize the variation of the chemical profiles among workers of the stingless bee Melipona marginata, and (2) to investigate the dependence of the chemical profiles on the age and on the behavior of the studied individuals. The results showed that cuticular hydrocarbon profiles of workers were composed of alkanes, alkenes and alkadienes that varied quantitatively and qualitatively according to function of workers in the colony. (C) 2010 Elsevier Ltd. All rights reserved.

LC-MS-MS Identification and Determination of the Flavone-C-Glucoside Vicenin-2 in Rat Plasma Samples Following Intraperitoneal Administration of Lychnophora Extract

The flavone C-glucoside, vicenin-2, in semi-purified extracts of the leaves of Lychnophora ericoides was quantified in rat plasma samples using a method based on reversed-phase high performance liquid chromatography coupled to tandem mass spectrometry. Vicenin-2 was analyzed on a LiChrospher (R) RP18 column using an isocratic mobile phase consisting of a mixture of methanol: water (30:70, v/v) plus 2.0% glacial acetic acid at a flow rate of 0.8 mL min(-1). Genistein was used as internal standard. The mass spectrometer was operated in positive ionization mode and analytes were quantified by multiple reaction monitoring at m/z 595 > 457 for vicenin-2 and m/z 271 > 153 for internal standard. Prior to the analysis, each rat plasma sample was acidified with 200 mu L of 50 mmol L(-1) acetic acid solution and extracted by solid-phase extraction using a C18 cartridge. The absolute recoveries were reproducible and the coefficients of variation values were lower than 5.2%. The method was linear over the 12.5 - 1500 ng mL(-1) concentration range and the quantification limit was 12.5 ng mL(-1). Within-day and between-day assay precision and accuracy were studied at three concentration levels (40, 400 and 800 ng mL(-1)) and were lower than 15%. The developed and validated method seems to be suitable for analysis of vicenin-2 in plasma samples obtained from rats that receive a single i.p. dose of 200 mg kg(-1) vicenin-2 extract.

A Validated Reverse-phase HPLC Analytical Method for the Quantification of Phenolic Compounds in Baccharis dracunculifolia

Introduction - Baccharis dracunculifolia, which has great potential for the development of new phytotherapeutic medicines, is the most important botanical source of the southeastern Brazilian propolis, known as green propolis on account of its color. Objective - To develop a reliable reverse-phase HPLC chromatographic method for the analysis of phenolic compounds in both B. dracunculifolia raw material and its hydroalcoholic extracts. Methodology - The method utilised a C(18) CLC-ODS (M) (4.6 x 250 mm) column with nonlinear gradient elution and UV detection at 280 nm. A procedure for the extraction of phenolic compounds using aqueous ethanol 90%, with the addition of veratraldehyde as the internal standard, was developed allowing the quantification of 10 compounds: caffeic acid, coumaric acid, ferulic acid, cinnamic acid, aromadendrin-4`-methyl ether, isosakuranetin, drupanin, artepillin C, baccharin and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran acid. Results - The developed method gave a good detection response with linearity in the range 20.83-800 mu g/mL and recovery in the range 81.25-93.20%, allowing the quantification of the analysed standards. Conclusion - The method presented good results for the following parameters: selectivity, linearity, accuracy, precision, robustness, as well as limit of detection and limit of quantitation. Therefore, this method could be considered as an analytical tool for the quality control of B. dracunculifolia raw material and its products in both cosmetic and pharmaceutical companies. Copyright (C) 2008 John Wiley & Sons, Ltd.

Development and validation of HPLC method for imiquimod determination in skin penetration studies

A simple, rapid and sensitive analytical procedure for the measurement of imiquimod in skin samples after in vitro penetration studies has been developed and validated. In vitro penetration studies were carried out in Franz diffusion cells with porcine skin. Tape stripping technique was used to separate the stratum corneum (SC) from the viable epidermis and dermis. Imiquimod was extracted from skin samples using a 7:3 (v/v) methanol:acetate buffer (100 mm, pH 4.0) solution and ultrasonication. Imiquimod was analyzed by H-PLC using C(8) column and UV detection at 242 ran. The mobile phase used was acetonitrile:acetate buffer (pH 4.0, 100 mM):diethylamine (30:69.85:0.15, v/v) with flow rate 1 mL/min. Imiquimod eluted at 4.1 min and the running time was limited to 6.0 min. The procedure was linear across the following concentration ranges: 100-2500 ng/mL for both SC and tape-stripped skin and 20-800 ng/mL for receptor solution. Intra-day and inter-day accuracy and precision values were lower than 20% at the limit of quantitation. The recovery values ranged from 80 to 100%. The method is adequate to assay imiquimod from skin samples, enabling the determination of the cutaneous penetration profile of uniquimod by in vitro studies. Copyright (C) 2008 John Wiley & Sons, Ltd.

Seasonal Variation of the (E)-Nerolidol and Other Volatile Compounds Within Ten Different Cultivated Populations of Baccharis dracunculifolia DC (Asteraceae)

Initially, the seeds of Baccharis dracunculifolia were collected from populations of 10 different regions, and the cultivation experiment was carried out in an experimental area of 1,800 m(2) by cultivating 100 individuals of each population. The essential oil analyses were performed on both GC-FID and GUMS, which allowed the identification of 14 compounds. The oil yield varied from 0.31% to 0.70% among populations and season. The major oxygenated sesquiterpenes in the cultivated experiment were (E)-nerolidol (32%) and spathulenol (17%). The mean concentration in the plant of (E)-nerolidol was five times higher in March (136.53 mg/100 g of plant) than it was in July (25.03 mg/100 g of plant). The mean concentration of spathulenol increased about three fold from July (16.25 mg/100 g of plant) to April (47.50 mg/100 g of plant).

Platinum nanoparticles embledded in layer-by-layer films from SnO2/polyallylamine for ethanol electrooxidation

Self-assembled films from SnO2 and polyallylamine (PAH) were deposited on gold via ionic attraction by the layer-by-layer(LbL) method. The modified electrodes were immersed into a H2PtCl6 solution, a current of 100 mu A was applied, and different electrodeposition times were used. The SnO2/PAH layers served as templates to yield metallic platinum with different particle sizes. The scanning tunnel microscopy images show that the particle size increases as a function of electrodeposition time. The potentiodynamic profile of the electrodes changes as a function of the electrodeposition time in 0.5 mol L-1 H2SO4, at a sweeping rate of 50mVs(-1). Oxygen-like species are formed at less positive potentials for the Pt-SnO2/PAH film in the case of the smallest platinum particles. Electrochemical impedance spectroscopy measurements in acid medium at 0.7 V show that the charge transfer resistance normalized by the exposed platinum area is 750 times greater for platinum electrode (300 k Omega cm(2)) compared with the Pt-SnO2/PAH film with 1 min of electrodeposition (0.4 k Omega cm(2)). According to the Langmuir-Hinshelwood bifunctional mechanism, the high degree of coverage with oxygen-like species on the platinum nanoparticles is responsible for the electrocatalytic activity of the Pt-SnO2/PAH concerning ethanol electrooxidation. With these features, this Pt-SnO2/PAH film may be grown on a proton exchange membrane (PEM) in direct ethanol fuel cells (DEFC). (c) 2008 Elsevier B.V. All rights reserved.

The Effect of Expectancy of a Threatening Event on Time Perception in Human Adults

Two experiments were conducted to investigate the effect of a threatening stimulus in human adults in a temporal bisection task. In Experiment I. for two anchor duration conditions (400/800 vs. 800/1600 ms), the participants completed trials in which the probe duration was followed by an aversive stimulus or a nonaversive stimulus. The results showed that the duration was judged longer when the participants expected an aversive rather than a nonaversive stimulus. In Experiment 2, the effect of the temporal localization of the aversive stimulus was also tested, with the aversive stimulus being presented at the beginning or at the end of the probe duration. The results revealed a temporal overestimation in each condition compared to the trials in which no aversive stimulus was presented. Furthermore, the temporal overestimation was greater when the expectation for the forthcoming threatening stimulus was longer. This temporal overestimation is explained in terms of a speeding-up of the neural timing system in response to the increase in the arousal level produced by the expectation of a threatening stimulus.

Effects of carbohydrate supplementation on competitive runners undergoing overload training followed by a session of intermittent exercise

This study evaluated the effects of a micro cycle of overload training (1st-8th day) on metabolic and hormonal responses in male runners with or without carbohydrate supplementation and investigated the cumulative effects of this period on a session of intermittent high-intensity running and maximum-performance-test (9th day). The participants were 24 male runners divided into two groups, receiving 61% of their energy intake as CHO (carbohydrate-group) and 54% in the control-group (CON). The testosterone was higher for the CHO than the CON group after the overload training (694.0 +/- A 54.6 vs. CON 610.8 +/- A 47.9 pmol/l). On the ninth day participants performed 10 x 800 m at mean 3 km velocity. An all-out 1000 m running was performed before and after the 10 x 800 m. Before, during, and after this protocol, the runners received solution containing CHO or the CON equivalent. The performance on 800 m series did not differ in either group between the first and last series of 800 m, but for the all-out 1000 m test the performance decrement was lower for CHO group (5.3 +/- A 1.0 vs. 10.6 +/- A 1.3%). The cortisol concentrations were lower in the CHO group in relation to CON group (22.4 +/- A 0.9 vs. 27.6 +/- A 1.4 pmol/l) and the IGF1/IGFBP3 ratio increased 12.7% in the CHO group. During recovery, blood glucose concentrations remained higher in the CHO group in comparison with the CON group. It was concluded that CHO supplementation possibly attenuated the suppression of the hypothalamic-pituitary-gonadal axis and resulted in less catabolic stress, and thus improved running performance.

Left ventricular Systolic function and outcome after in-hospital cardiac arrest

Background - The effect of prearrest left ventricular ejection fraction ( LVEF) on outcome after cardiac arrest is unknown. Methods and Results - During a 26-month period, Utstein-style data were prospectively collected on 800 consecutive inpatient adult index cardiac arrests in an observational, single-center study at a tertiary cardiac care hospital. Prearrest echocardiograms were performed on 613 patients ( 77%) at 11 +/- 14 days before the cardiac arrest. Outcomes among patients with normal or nearly normal prearrest LVEF ( >= 45%) were compared with those of patients with moderate or severe dysfunction ( LVEF < 45%) by chi(2) and logistic regression analyses. Survival to discharge was 19% in patients with normal or nearly normal LVEF compared with 8% in those with moderate or severe dysfunction ( adjusted odds ratio, 4.8; 95% confidence interval, 2.3 to 9.9; P < 0.001) but did not differ with regard to sustained return of spontaneous circulation ( 59% versus 56%; P = 0.468) or 24-hour survival ( 39% versus 36%; P = 0.550). Postarrest echocardiograms were performed on 84 patients within 72 hours after the index cardiac arrest; the LVEF decreased 25% in those with normal or nearly normal prearrest LVEF ( 60 +/- 9% to 45 +/- 14%; P < 0.001) and decreased 26% in those with moderate or severe dysfunction ( 31 +/- 7% to 23 +/- 6%, P < 0.001). For all patients, prearrest beta-blocker treatment was associated with higher survival to discharge ( 33% versus 8%; adjusted odds ratio, 3.9; 95% confidence interval, 1.8 to 8.2; P < 0.001). Conclusions - Moderate and severe prearrest left ventricular systolic dysfunction was associated with substantially lower rates of survival to hospital discharge compared with normal or nearly normal function.

Peginterferon alfa-2b and Ribavirin: Effective in Patients With Hepatitis C Who Failed Interferon alfa/Ribavirin Therapy

Background & Aims: Treatment with peginterferon alfa and ribavirin produces a sustained virologic response (SVR) in approximately 60% of hepatitis C virus (HCV)-infected patients. Alternate options are needed for patients who relapse or do not respond to therapy. Methods: This prospective, international, multicenter, open-label study evaluated efficacy and safety of peginterferon alfa-2b (1.5 mu g/kg/wk) plus weight-based ribavirin (800-1400 mg/day) in 2333 chronic HCV-infected patients with significant fibrosis/cirrhosis whose previous interferon alfa/ribavirin therapy failed. Patients with undetectable HCV-RNA at treatment week (TW) 12 received 48 weeks of therapy; patients with detectable HCV-RNA at TW12 could enter maintenance studies at TW18; 188 patients with low/detectable HCV-RNA at TW12 continued therapy at the investigator`s request. Results: Overall, 22% of the patients attained SVR (56% with undetectable HCV-RNA and 12% with low/detectable HCV-RNA at TW12). SVR was better in relapsers (38%) than nonresponders (14%), regardless of previous treatment, and in patients previously treated with interferon-alfa/ribavirin (25%) than peginterferon alfa-ribavirin (17%). Predictors of response in patients with undetectable HCV-RNA at TW12 were genotype (2/3 vs 1, respectively; odds ratio [OR] 2.4; P < .0001), fibrosis score (F2 vs F4; OR, 2.2; F3 vs F4; OR, 1.7; P < .0001), and baseline viral load (<= 600,000 vs >600,000 IU/mL; OR, 1.4; P = .0223). These factors plus previous treatment and response were overall predictors of SVR. Safety was similar among fibrosis groups. Conclusions: Peginterferon alfa-2b plus weight-based ribavirin is effective and safe in patients who failed interferon alfa/ribavirin therapy. Genotype, baseline viral load, and fibrosis stage were predictors of response.

Multiple ADH genes are associated with upper aerodigestive cancers

Alcohol is an important risk factor for upper aerodigestive cancers and is principally metabolized by alcohol dehydrogenase (ADH) enzymes. We have investigated six ADH genetic variants in over 3,800 aerodigestive cancer cases and 5,200 controls from three individual studies. Gene variants rs1229984 (ADH1B) and rs1573496 (ADH7) were significantly protective against aerodigestive cancer in each individual study and overall (P = 10(-10) and 10(-9), respectively). These effects became more apparent with increasing alcohol consumption (P for trend = 0.0002 and 0.065, respectively). Both gene effects were independent of each other, implying that multiple ADH genes may be involved in upper aerodigestive cancer etiology.

Chronic nasal instillation of residual-oil fly ash (ROFA) induces brain lipid peroxidation and behavioral changes in rats

Several epidemiological studies have linked particulate matter exposure to numerous adverse health effects on the respiratory, cardiovascular, and reproductive systems (Braga et al., 1999; Zanobetti et al., 2000; Anderson et al., 2001; Farhat et al., 2005). More recently, ambient levels of black carbon were associated to impaired cognitive function in children (Suglia et al., 2008), suggesting that the central nervous system (CNS) may be a target of air pollutants. The present study was conducted to (a) determine whether chronic residual oil fly ash (ROFA) exposure promotes behavioral changes and lipid peroxidation in rat brain areas, and (b) determine whether N-acetylcysteine (NAC), a general antioxidant, prevents these effects. Forty-five-day-old male Wistar rats were exposed or not to ROFA by intranasal instillation and were treated or not with NAC (150 mg/kg) ip for 30 days. One day later, rats were submitted to the open field test to evaluate the motor/exploratory activities and emotionality followed by decapitation. Striatum and cerebellum were dissected to determine lipid peroxidation by the accumulation of thiobarbituric acid-reactive substances (TBARS). ROFA instillation induced an increase in lipid peroxidation level in striatum (p = .033) and cerebellum (p = .030), as compared with the control group. NAC treatment blocked these changes. ROFA promoted a decrease in the frequency of peripheral walking (p = .006) and a decrease in exploration (p = .001), which were not blocked by N-acetylcysteine. The present study provides evidence that toxic particles, administered by the respiratory route, induce oxidative stress in structures of the central nervous system, as well as behavioral alterations. The administration of NAC reduces lipid peroxidation at the striatum and cerebellum levels, but does not influence behavioral disturbances.

Clinical usefulness of B-type natriuretic peptide in the diagnosis of pleural effusions due to heart failure

Background and objective: Light`s criteria are frequently used to evaluate the exudative or transudative nature of pleural effusions. However, misclassification resulting from the use of Light`s criteria has been reported, especially in the setting of diuretic use in patients with heart failure (HF). The objective of this study was to evaluate the utility of B-type natriuretic peptide (BNP) measurements as a diagnostic tool for determining the cardiac aetiology of pleural effusions. Methods: Patients with pleural effusions attributable to HF (n = 34), hepatic hydrothorax (n = 10), pleural effusions due to cancer (n = 21) and pleural effusions due to tuberculosis (n = 12) were studied. Diagnostic thoracentesis was performed for all 77 patients. Receiver operating characteristic (ROC) curves were constructed to determine the diagnostic accuracy of plasma BNP and pleural fluid BNP for the prediction of HF. Results: The areas under the ROC curves were 0.987 (95% CI 0.93-0.998) for plasma BNP and 0.949 (95% CI 0.874-0.986) for pleural fluid BNP, for distinguishing between patients with pleural effusions caused by HF (n = 34) and those with pleural effusions attributable to other causes (n = 43). The cut-off concentrations with the highest diagnostic accuracy for the diagnosis of HF as the cause of pleural effusion were 132 pg/mL for plasma BNP (sensitivity 97.1%, specificity 97.4%) and 127 pg/mL for pleural fluid BNP (sensitivity 97.1%, specificity 87.8%). Conclusions: In patients with pleural effusions of suspected cardiac origin, measurements of BNP in plasma and pleural fluid may be useful for the diagnosis of HF as the underlying cause.

Effect of Disease Severity on the Performance of Cirrus Spectral-Domain OCT for Glaucoma Diagnosis

PURPOSE. To evaluate the effect of disease severity on the diagnostic accuracy of the Cirrus Optical Coherence Tomograph (Cirrus HD-OCT; Carl Zeiss Meditec, Inc., Dublin, CA) for glaucoma detection. METHODS. One hundred thirty-five glaucomatous eyes of 99 patients and 79 normal eyes of 47 control subjects were recruited from the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS). The severity of the disease was graded based on the visual field index (VFI) from standard automated perimetry. Imaging of the retinal nerve fiber layer (RNFL) was obtained using the optic disc cube protocol available on the Cirrus HD-OCT. Pooled receiver operating characteristic (ROC) curves were initially obtained for each parameter of the Cirrus HD-OCT. The effect of disease severity on diagnostic performance was evaluated by fitting an ROC regression model, with VFI used as a covariate, and calculating the area under the ROC curve (AUCs) for different levels of disease severity. RESULTS. The largest pooled AUCs were for average thickness (0.892), inferior quadrant thickness (0.881), and superior quadrant thickness (0.874). Disease severity had a significant influence on the detection of glaucoma. For the average RNFL thickness parameter, AUCs were 0.962, 0.932, 0.886, and 0.822 for VFIs of 70%, 80%, 90%, and 100%, respectively. CONCLUSIONS. Disease severity had a significant effect on the diagnostic performance of the Cirrus HD-OCT and thus should be considered when interpreting results from this device and when considering the potential applications of this instrument for diagnosing glaucoma in the various clinical settings. (Invest Ophthalmol Vis Sci. 2010;51:4104-4109) DOI:10.1167/iovs.094716

Nasal eosinophilia: an indicator of eosinophilic inflammation in asthma

Background It is noteworthy that there is a clear clinical, epidemiological and pathophysiological association between upper and lower airway inflammation in rhinitis and asthma. Objective The aim of this study was to compare the eosinophil counts in induced sputum and nasal lavage fluids in asthma, checking their association and the accuracy of nasal eosinophilia as a predictor of sputum eosinophilia by a cross-sectional study. Methods The clinical evaluation, asthma control questionnaire (ACQ), pre- and post-bronchodilator spirometry, nasal and sputum sample was performed. The nasal eosinophilia was analysed by a receiver operating curve and logistic regression model. Results In 140 adults, the post-bronchodilator forced expiratory volume in 1 s (FEV(1)) did not differ between patients with or without sputum eosinophilia (0.18). After adjusted for upper airway symptoms, age, ACQ score and post-bronchodilator FEV(1), sputum eosinophilia was associated with 52 times increase in odds of nasal eosinophilia, whereas each 1% increase in bronchodilator response was associated with 7% increase in odds of nasal eosinophilia. Conclusion This study brings further evidence that upper airway diseases are an important component of the asthma syndrome. Furthermore, monitoring of nasal eosinophilia by quantitative cytology may be useful as a surrogate of sputum cytology in as a component of composite measurement for determining airway inflammation.