Relationship between ethanol and sucrose self-administration and schedule-induced polydipsia

Studies have suggested a relationship between drug abuse and compulsive behaviors. The present experiments investigated the relationship between schedule-induced polydipsia (SIP) and self-administration (SA) of ethanol and sucrose. SIP served as a model of compulsive behavior. and oral self-administration on a progressive-ratio (PR) schedule of reinforcement assessed the reinforcing value of either a 10% ethanol solution or an isocaloric sucrose solution. Rats first were exposed to PR sessions in which break points were the dependent variable and then switched to SIP sessions. with number of licks as the dependent variable. Results showed a positive relationship between PR and SIP for sucrose but not for ethanol: higher and lower PRs for sucrose were associated with higher and lower SIP levels. The order of the sessions then was reversed, such that SIP sessions were run before PR sessions. An opposite relationship was observed in which high and low SIP animals exhibited low and high PR break points, respectively. The relationship between SIP and SA was dependent on the reinforcing value of the substance and on prior SIP exposure. These results may reflect a common dopaminergic substrate and suggest that prior experience in coping with stress may reduce vulnerability to substance abuse behavior. (c) 2008 Published by Elsevier Inc.

Alterations in pulmonary structure by elastase administration in a model of emphysema in mice is associated with functional disturbances

Several experimental studies of pulmonary emphysema using animal models have been described in the literature. However, only a few of these studies have focused on the assessment of ergometric function as a non-invasive technique to validate the methodology used for induction of experimental emphysema. Additionally, functional assessments of emphysema are rarely correlated with morphological pulmonary abnormalities caused by induced emphysema. The present study aimed to evaluate the effects of elastase administered by tracheal puncture on pulmonary parenchyma and their corresponding functional impairment. This was evaluated by measuring exercise capacity in C57Bl/6 mice in order to establish a reproducible and safe methodology of inducing experimental emphysema. Thirty six mice underwent ergometric tests before and 28 days after elastase administration. Pancreatic porcine elastase solution was administered by tracheal puncture, which resulted in a significantly decreased exercise capacity, shown by a shorter distance run (-30.5%) and a lower mean velocity (-15%), as well as in failure to increase the elimination of carbon dioxide. The mean linear intercept increased significantly by 50% in tracheal elastase administration. In conclusion, application of elastase by tracheal function in C57Bl/6 induces emphysema, as validated by morphometric analyses, and resulted in a significantly lower exercise capacity, while resulting in a low mortality rate. (C) 2011 Sociedade Portuguesa de Pneumologia. Published by Elsevier Espana, S.L. All rights reserved.

Field and laboratory studies to assess the effects of Vertimec (R) 18EC on Daphnia similis

The present study aimed to evaluate the interactions of the pesticide Vertimec (R) 18EC in aquatic ecosystems. In this respect, soil plots were contaminated with Vertimec (R) 18EC at the concentration indicated for strawberry crops (0.125 L of solution m(-2)). After the contamination, torrential rainfall was simulated and the surface runoff was collected and transferred to mesocosm tanks in five treatments, run in triplicate: (1) control-C; (2) runoff from an uncontaminated plot-UR; (3) runoff from the plot contaminated with Vertimec (R) 18EC-CR; (4) direct application of Vertimec (R) 18EC in the water-V and (5) water samples gathered randomly to verify whether there was contamination between the mesocosms-RS. Water samples from these tanks were also submitted to ecotoxicological tests with Daphnia similis and analyses to evaluate the limnological characteristics, in five collection periods over 10 days (240 h). Physical and chemical differences were observed in the water samples, mainly related to increased turbidity, suspended solids and nutrients (nitrogen and phosphate forms). Acute toxicity was observed for the direct application treatment for the entire experimental period, and in some periods for the CR treatment (from 48 h to 168 h). The results obtained suggest that the pesticide did not fully degrade during the study period (10 days) in the direct application treatment, demonstrating that the presence of other substances in the commercial formulation contribute to the maintenance of toxicity. This represents a potential risk for aquatic ecosystems in areas adjacent to where the chemical is applied. (C) 2011 Elsevier Inc. All rights reserved.

Reconnection studies under different types of turbulence driving

We study a model of fast magnetic reconnection in the presence of weak turbulence proposed by Lazarian and Vishniac (1999) using three-dimensional direct numerical simulations. The model has been already successfully tested in Kowal et al. (2009) confirming the dependencies of the reconnection speed V-rec on the turbulence injection power P-inj and the injection scale l(inj) expressed by a constraint V-rec similar to P(inj)(1/2)l(inj)(3/4)and no observed dependency on Ohmic resistivity. In Kowal et al. (2009), in order to drive turbulence, we injected velocity fluctuations in Fourier space with frequencies concentrated around k(inj) = 1/l(inj), as described in Alvelius (1999). In this paper, we extend our previous studies by comparing fast magnetic reconnection under different mechanisms of turbulence injection by introducing a new way of turbulence driving. The new method injects velocity or magnetic eddies with a specified amplitude and scale in random locations directly in real space. We provide exact relations between the eddy parameters and turbulent power and injection scale. We performed simulations with new forcing in order to study turbulent power and injection scale dependencies. The results show no discrepancy between models with two different methods of turbulence driving exposing the same scalings in both cases. This is in agreement with the Lazarian and Vishniac (1999) predictions. In addition, we performed a series of models with varying viscosity nu. Although Lazarian and Vishniac (1999) do not provide any prediction for this dependence, we report a weak relation between the reconnection speed with viscosity, V-rec similar to nu(-1/4).

Hepatitis B virus genotypes from European origin explains the high endemicity found in some areas from southern Brazil

Southern Brazil is considered an area of low Hepatitis B endemicity, but some areas of higher endemicity have been described in the Southwest of Parana and Santa Catarina states. The aim of this study was to evaluate viral genotypes circulating throughout Parana state. PCR amplification and partial sequencing of the S gene was carried out in 228 samples from HBsAg positive candidate blood donors. Samples have been collected in seven different counties (Cascavel, Curitiba, Foz do Iguacu, Francisco Beltrao, Matinga Londrina and Paranagua). The most common HBV genotype in Parana state was D (82.9%; 189/228), followed by A (14.1%; 32/228). Genotypes F (1.3%; 3/228), C (1.3%; 3/228) and H (0.4%; 1/228) were also found. Distribution of genotypes was different in the studied counties, but genotype D was the most frequent in all of them. In Francisco Beltrao, all studied samples belonged to genotype D. The high prevalence of HBV genotype Din South of Brazil is explained by the intense migration of settlers from Europeans countries. Subgenotypes A1 and A2 were identified circulating in all cities where HBV/A was found. As observed in other areas of Brazil, HBV/A1 is more frequent than the HBV/A2 in Parana state and its presence was significantly larger in black and mulatto individuals. Genotype C was found only in individuals with Asian ancestry from Londrina and Maringa. Most HBV/F sequences identified in this study were classified as subgenotype F2a that was previously described in Brazil. The sole case of subgenotype F4 was from Foz do Iguacu city, near to Northern Argentina, where F4 is highly prevalent. The single genotype H sample was from Curitiba. This is the first case of this genotype described in Brazil. Further studies should be carried out to determine if more genotype H samples can be found in other populations from Brazil. (C) 2012 Elsevier B.V. All rights reserved.

Infant mortality in Brazil, 1980-2000: A spatial panel data analysis

Background: Infant mortality is an important measure of human development, related to the level of welfare of a society. In order to inform public policy, various studies have tried to identify the factors that influence, at an aggregated level, infant mortality. The objective of this paper is to analyze the regional pattern of infant mortality in Brazil, evaluating the effect of infrastructure, socio-economic, and demographic variables to understand its distribution across the country. Methods: Regressions including socio-economic and living conditions variables are conducted in a structure of panel data. More specifically, a spatial panel data model with fixed effects and a spatial error autocorrelation structure is used to help to solve spatial dependence problems. The use of a spatial modeling approach takes into account the potential presence of spillovers between neighboring spatial units. The spatial units considered are Minimum Comparable Areas, defined to provide a consistent definition across Census years. Data are drawn from the 1980, 1991 and 2000 Census of Brazil, and from data collected by the Ministry of Health (DATASUS). In order to identify the influence of health care infrastructure, variables related to the number of public and private hospitals are included. Results: The results indicate that the panel model with spatial effects provides the best fit to the data. The analysis confirms that the provision of health care infrastructure and social policy measures (e. g. improving education attainment) are linked to reduced rates of infant mortality. An original finding concerns the role of spatial effects in the analysis of IMR. Spillover effects associated with health infrastructure and water and sanitation facilities imply that there are regional benefits beyond the unit of analysis. Conclusions: A spatial modeling approach is important to produce reliable estimates in the analysis of panel IMR data. Substantively, this paper contributes to our understanding of the physical and social factors that influence IMR in the case of a developing country.

Parasites in the neighbourhood: Interactions of the mistletoe Phoradendron affine (Viscaceae) with its dispersers and hosts in urban areas of Brazil

Mistletoes constitute an important food resource for animals in many ecosystems. However, these plants are considered pests in urban areas because of deleterious effects they have on the host trees. Studies in urban areas were mostly focused on listing host species or procedures to control the "pest". In this sense, broader studies including several aspects of mistletoes ecology in urban ecosystems are still missing. We studied the interaction of the mistletoe, Phoradendron affine, with its dispersers and hosts in two urban sites in Uberlandia, Brazil. Phoradendron affine fruits were consumed almost exclusively by Euphonia chlorotica, which was crucial for seed germination. Parasitism was recorded in five hosts, two native (Handroanthus chrysotrichus and Tabebuia roseoalba) and three exotic species (Spathodea campanulata, Ligustrum lucidum and Melia azedarach). Mistletoes were found parasitizing larger host trees, a trend commonly reported for mistletoe-host interaction. Mistletoe seed germination was not affected by the trees species, whether host or non-host, but the radicle of germinated seeds could not penetrate the bark and seedlings invariably died in non-host species. We found a high prevalence of parasitism in our study, in comparison to what previous studies reported for natural areas. The spatial distribution of the hosts and high light incidence on isolated host trees may lead to this high prevalence in urban areas. Rather than eradicated, mistletoes in urban areas should be ecologically managed and their importance for bird species conservation must be considered. More studies to determine which bird species are favoured by mistletoe presence in urban areas will be essential for, this purpose. (C) 2012 Elsevier GmbH. All rights reserved.

Acute cocaine treatment increases thimet oligopeptidase in the striatum of rat brain

Many studies indicate that thimet oligopeptidase (EC3.4.24.15; TOP) can be implicated in the metabolism of bioactive peptides, including dynorphin 1-8, alpha-neoendorphin, beta-neoendorphin and GnRH. Furthermore, the higher levels of this peptidase are found in neuroendocrine tissue and testis. In the present study, we have evaluated the effect of acute cocaine administration in male rats on TOP specific activity and mRNA levels in prosencephalic brain areas related with the reward circuitry; ventral striatum, hippocampus, and frontal cortex. No significant differences on TOP specific activity were detected in the hippocampus and frontal cortex of cocaine treated animals compared to control vehicle group. However, a significant increase in activity was observed in the ventral striatum of cocaine treated-rats. The increase occurred in both, TOP specific activity and TOP relative mRNA amount determined by real time RT-PCR. As TOP can be implicated in the processing of many neuropeptides, and previous studies have shown that cocaine also alters the gene expression of proenkephalin and prodynorphin in the striatum, the present findings suggest that TOP changes in the brain could play important role in the balance of neuropeptide level correlated with cocaine effects. (C) 2012 Elsevier Inc. All rights reserved.

WHAT THE STUDIES CONDUCTED IN BRAZIL REGARDING DIVIDEND POLICY REVEAL

This paper consists of a review of the literature about dividend policy in Brazil, focusing on the empirical studies conducted from 1990 to 2010 that were published in major Brazilian administration, accounting and finance journals and major conference proceedings on this subject. The analyzed sample comprised 39 studies using various methods and conducted in various periods. Based on the model of Harris and Raviv (1991), this paper grouped studies according to model type, and it found five main categories. We were able to find some tendencies, such as: dividend policy relevance in the Brazilian market; confirmation of existence of agency problems; conflicting findings regarding the clientele hypothesis; tax signaling in, and tax impact on, defining dividend policy; non-conflicting findings regarding key factors of dividend policy..

Thermal studies on protein isolates of white lupin seeds (Lupinus albus)

This study used TG, DSC, and SDS-PAGE techniques to study protein isolates (PIs) in the powder form obtained from lupin seeds flour Lupinus albus. Different methods of preparing PIs were tested, resulting in final products that were different only in relation to the yield and protein content. The results of the protein analysis by SDS-PAGE showed that the same protein fractions were present in the lupin seeds and in the obtained PIs. This result shows that the process of extraction was not damaging to the composition of the original protein. On the other hand, the results of the thermal analysis (DSC and TG-DTG curves) obtained for the different PIs, led to the detection of changes in the protein conformation through the Delta H values, which in general decreased with increasing values of pH and ionic strength in the experimental conditions of extraction.

Effects of 3 weeks GMP oral administration on glutamatergic parameters in mice neocortex

Overstimulation of the glutamatergic system (excitotoxicity) is involved in various acute and chronic brain diseases. Several studies support the hypothesis that guanosine-5'-monophosphate (GMP) can modulate glutamatergic neurotransmission. The aim of this study was to evaluate the effects of chronically administered GMP on brain cortical glutamatergic parameters in mice. Additionally, we investigated the neuroprotective potential of the GMP treatment submitting cortical brain slices to oxygen and glucose deprivation (OGD). Moreover, measurements of the cerebrospinal fluid (CSF) purine levels were performed after the treatment. Mice received an oral administration of saline or GMP during 3 weeks. GMP significantly decreases the cortical brain glutamate binding and uptake. Accordingly, GMP reduced the immunocontent of the glutamate receptors subunits, NR2A/B and GluR1 (NMDA and AMPA receptors, respectively) and glutamate transporters EAAC1 and GLT1. GMP treatment significantly reduced the immunocontent of PSD-95 while did not affect the content of Snap 25, GLAST and GFAP. Moreover, GMP treatment increased the resistance of neocortex to OGD insult. The chronic GMP administration increased the CSF levels of GMP and its metabolites. Altogether, these findings suggest a potential modulatory role of GMP on neocortex glutamatergic system by promoting functional and plastic changes associated to more resistance of mice neocortex against an in vitro excitotoxicity event.

Trabecular bone loss after administration of the second-generation antipsychotic risperidone is independent of weight gain

Second generation antipsychotics (SGAs) have been linked to metabolic and bone disorders in clinical studies, but the mechanisms of these side effects remain unclear. Additionally, no studies have examined whether SGAs cause bone loss in mice. Using in vivo and in vitro modeling we examined the effects of risperidone, the most commonly prescribed SGA, on bone in C57BL6/J (B6) mice. Mice were treated with risperidone orally by food supplementation at a dose of 1.25 mg/kg daily for 5 and 8 weeks, starting at 3.5 weeks of age. Risperidone reduced trabecular BV/TV, trabecular number and percent cortical area. Trabecular histomorphometry demonstrated increased resorption parameters, with no change in osteoblast number or function. Risperidone also altered adipose tissue distribution such that white adipose tissue mass was reduced and liver had significantly higher lipid infiltration. Next, in order to tightly control risperidone exposure, we administered risperidone by chronic subcutaneous infusion with osmotic minipumps (0.5 mg/kg daily for 4 weeks) in 7 week old female B6 mice. Similar trabecular and cortical bone differences were observed compared to the orally treated groups (reduced trabecular BV/TV, and connectivity density, and reduced percent cortical area) with no change in body mass, percent body fat, glucose tolerance or insulin sensitivity. Unlike in orally treated mice, risperidone infusion reduced bone formation parameters (serum P1NP, MAR and BFR/BV). Resorption parameters were elevated, but this increase did not reach statistical significance. To determine if risperidone could directly affect bone cells, primary bone marrow cells were cultured with osteoclast or osteoblast differentiation media. Risperidone was added to culture medium in clinically relevant doses of 0, 2.5 or 25 ng/ml. The number of osteoclasts was significantly increased by addition in vitro of risperidone while osteoblast differentiation was not altered. These studies indicate that risperidone treatment can have negative skeletal consequences by direct activation of osteoclast activity and by indirect non-cell autonomous mechanisms. Our findings further support the tenet that the negative side effects of SGAs on bone mass should be considered when weighing potential risks and benefits, especially in children and adolescents who have not yet reached peak bone mass. This article is part of a Special Issue entitled: Interactions Between Bone, Adipose Tissue and Metabolism. (C) 2011 Elsevier Inc. All rights reserved.

Novelty, but Not Operant Aversive Learning, Enhances Fos and Egr-1 Expression in the Medial Prefrontal Cortex and Hippocampal Areas of Rats

Immediate early genes (IEG) are presumed to be activated in response to stress, novelty, and learning. Evidence supports the involvement of prefrontal and hippocampal areas in stress and learning, but also in the detection of novel events. This study examined whether a previous experience with shocks changes the pattern of Fos and Egr-1 expression in the medial prefrontal cortex (mPFC), the hippocampal cornus ammonis 1 (CA1), and dentate gyrus (DG) of adult male Wistar rats that learned to escape in an operant aversive test. Subjects previously exposed to inescapable footshocks that learned to escape from Shocks were assigned to the treated group (EXP). Subjects from Group Novelty (NOV) rested undisturbed during treatment and also learned to escape in the test. The nonshock group (NSH) rested undisturbed in both sessions. Standard immunohistochemistry procedures were used to detect the proteins in brain sections. The results show that a previous experience with shocks changed the pattern of IEG expression, then demonstrating c-fos and egr-1 induction as experience-dependent events. Compared with NSH and EXP an enhanced Fos expression was detected in the mPFC and CA1 subfield of Group NOV, which also exhibited increased Egr-1 expression in the mPFC and DG in comparison to NSH. No differences were found in the DG for Fos, or in the CA1 for Egr-1. Novelty, and not the operant aversive escape learning, seems to have generated IEG induction. The results suggest novel stimuli as a possible confounding factor in studies on Fos and/or Egr-1 expression in aversive conditions.

17 beta-Estradiol replacement in young, adult and middle-aged female ovariectomized rats promotes improvement of spatial reference memory and an antidepressant effect and alters monoamines and BDNF levels in memory- and depression-related brain areas

Clinical and experimental evidence suggest that estrogens have a major impact on cognition, presenting neurotrophic and neuroprotective actions in regions involved in such function. In opposite, some studies indicate that certain hormone therapy regimens may provoke detrimental effects over female cognitive and neurological function. Therefore, we decided to investigate how estrogen treatment would influence cognition and depression in different ages. For that matter, this study assessed the effects of chronic 17 beta-estradiol treatment over cognition and depressive-like behaviors of young (3 months old), adult (7 months old) and middle-aged (12 months old) reproductive female Wistar rats. These functions were also correlated with alterations in the serotonergic system, as well as hippocampal BDNF. 17 beta-Estradiol treatment did not influence animals' locomotor activity and exploratory behavior, but it was able to improve the performance of adult and middle-aged rats in the Morris water maze, the latter being more responsive to the treatment. Young and adult rats displayed decreased immobility time in the forced swimming test, suggesting an effect of 17 beta-estradiol also over such depressive-like behavior. This same test revealed increased swimming behavior, triggered by serotonergic pathway, in adult rats. Neurochemical evaluations indicated that 17 beta-estradiol treatment was able to increase serotonin turnover rate in the hippocampus of adult rats. Interestingly, estrogen treatment increased BDNF levels from animals of all ages. These findings support the notion that the beneficial effects of 17 beta-estradiol over spatial reference memory and depressive-like behavior are evident only when hormone therapy occurs at early ages and early stages of hormonal decline. (C) 2011 Elsevier B.V. All rights reserved.

Levels of selected persistent organic pollutants in blood from delivering women in seven selected areas of Sao Paulo State, Brazil

Persistent organic pollutants (POPS) present in the living environment are thought to have detrimental health effects on the population, with pregnant women and the developing foetus being at highest risk. We report on the levels of selected POPs in maternal blood of 155 delivering women residing in seven regions within the Sao Paulo State, Brazil. The following selected POPs were measured in the maternal whole blood: 12 polychlorinated biphenyls (PCBs) congeners (IUPAC Nos. 99, 101, 118, 138, 153, 156, 163, 170, 180, 183, 187, 194); dichlordiphenyltrichloroethane p,p'-DDT, diphenyldichloroethylene p,p'-DDE and other pesticides such as hexachlorocyclohexanes (alpha-HCH, beta-HCH, gamma-HCH), hexachlorobenzene (HCB), chlordane derivatives cis-chlordane, trans-chlordane. oxy-chlordane, cis-nonachlor and trans-nonachlor. Statistical comparisons between regions were performed only on compounds having concentrations above LOD in 70% of the samples. PCB118 congener was found to be highest in the industrial site (mean 4.97 ng/g lipids); PCB138 congener concentration was highest in the Urban 3 site (mean 4.27 ng/g lipids) and congener PCB153 was highest in the industrial and Urban 3 sites with mean concentration of 7.2 ng/g lipids and 5.89 ng/g lipids respectively. Large differences in levels of p,p'-DDE between regions were observed with the Urban 3 and industrial sites having the highest concentrations of 645 ng/g lipids and 417 ng/g lipids, respectively; beta-HCH was found to be highest in the Rural 1 site; the gamma-HCH in Rural 1 and industrial; the HCB in the Rural 1 and industrial sites and oxy-chlordane and t-NC in the Rural 2 sites. An association between levels of some contaminants and maternal age and parity was also found. (C) 2011 Elsevier Ltd. All rights reserved.