Suicide risk in epilepsy: Clinical variables, psychiatric disorders, and social support.

OBJECTIVE: To explore the relationship between suicide risk, the perception of social support and quality of life (QoL), and with the clinical variables of adult people with epilepsy (PWEs). METHODOLOGY: A total of 98 consecutive PWEs cared for in the outpatient setting, with a mean age of 48.1±15.9 years, having had epilepsy for 26.4±16.4 years and 48 (48.9%) female cases participated in this study. The MINI suicide module, the Social support satisfaction scale (SSSS), the Quality of life in epilepsy inventory (QOLIE-31), and the Hospital anxiety and depression scale (HADS) were used. A logistic regression was conducted to assess the factors associated with the suicide risk. RESULTS: Suicide risk was present in 33 cases. Younger age, earlier age at epilepsy onset, depression and anxiety in the HADS scale, and lower MMSE, QOLIE-31, and SSSS scores were significantly associated with suicide risk in the univariate analysis. The logistic regression analysis identified that lower scores in the MMSE (OR 0.826, 95%CI 0.705-0.969), presence of anxiety (OR 0.197, CI 0.073-0.530), and a low perception regarding satisfaction with family (OR 0.953, CI 0.920-0.988) are the factors associated with the highest risk of suicide. CONCLUSION: Suicide risk and recurrence of a suicide attempt was high in the PWEs. Suicide risk was associated with clinical variables, the presence of anxiety and the perception of less social support from the family.

Historical Pollution of an Urban Watershed Based in Geochemical, Geoacumulation, and EROD Activity in PLHC-1 Analyses in Sediment Cores.

In the present study, the environmental changes over the past 100 years in the Cambé River watershed in Southern Brazil were investigated. For this, a sediment core was collected to examine the distribution of metals, polycyclic aromatic hydrocarbons (PAHs), and ecotoxicological markers. The core corresponds from 1914 to 2012, which was obtained by the decay of 210Pb. Changes in the study area also were examined by: Geoaccumulation index (Igeo) and enrichment factor (EF), sediment quality guidelines (SGQs), and ethoxyresorufin-O-deethylase (EROD) activity in Poeciliopsis lucida hepatocellular carcinoma (PLHC-1) cells line. The Σ16 PAHs ranged from 242.6 to 40,775 ng g-1, with pyrogenic source at the beginning of the core, which likely corresponds to the burning of forests to establish the city and the later use of fossil fuels from 1960 to 2012. In the 1930s, most of metals presented a concentration below the background. After the 1930s, high concentrations can be associated with the intense use of fertilizers (Cd, Cu, Zn, Hg) and increases in urban traffic (Zn and Pb). Igeo showed that the distribution of Cu is considered moderately to strongly polluted, and the EF of Pb was considered as moderately polluted. Statistical analyses showed a strong relation between the presence of the ANP, FLU, PHE, BaP, IND, and Bghi compounds and the induction of EROD activity, and no correlation with heavy metals. A prediction model for the linear regression was obtained between the ANP and BaP concentrations and the EROD activity, with an accuracy of 99%.

Attenuation of ketamine-induced impairment in verbal learning and memory in healthy volunteers by the AMPA receptor potentiator PF-04958242.

There is a need to develop treatments for cognitive impairment associated with schizophrenia (CIAS). The significant role played by N-methyl-d-aspartate receptors (NMDARs) in both the pathophysiology of schizophrenia and in neuronal plasticity suggests that facilitation of NMDAR function might ameliorate CIAS. One strategy to correct NMDAR hypofunction is to stimulate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) as AMPAR and NMDAR functioning are coupled and interdependent. In rats and nonhuman primates (NHP), AMPAR potentiators reduce spatial working memory deficits caused by the nonselective NMDAR antagonist ketamine. The current study assessed whether the AMPAR potentiator PF-04958242 would attenuate ketamine-induced deficits in verbal learning and memory in humans. Healthy male subjects (n=29) participated in two randomized treatment periods of daily placebo or PF-04958242 for 5 days separated by a washout period. On day 5 of each treatment period, subjects underwent a ketamine infusion for 75 min during which the effects of PF-04958242/placebo were assessed on ketamine-induced: (1) impairments in verbal learning and recall measured by the Hopkins Verbal Learning Test; (2) impairments in working memory on a CogState battery; and (3) psychotomimetic effects measured by the Positive and Negative Syndrome Scale and Clinician-Administered Dissociative Symptoms Scale. PF-04958242 significantly reduced ketamine-induced impairments in immediate recall and the 2-Back and spatial working memory tasks (CogState Battery), without significantly attenuating ketamine-induced psychotomimetic effects. There were no pharmacokinetic interactions between PF-04958242 and ketamine. Furthermore, PF-04958242 was well tolerated. 'High-impact' AMPAR potentiators like PF-04958242 may have a role in the treatment of the cognitive symptoms, but not the positive or negative symptoms, associated with schizophrenia. The excellent concordance between the preclinical (rat, NHP) and human studies with PF-04958242, and in silico modeling of AMPAR-NMDAR interactions in the hippocampus, highlights the translational value of this study.

Selection of experimental strawberry (Fragaria x ananassa) hybrids based on selection indices.

The strawberry (Fragaria x ananassa Dutch.), is the only vegetable belonging to the rosacea family. All strawberry species have now emerged from wild species and belong to the genus Fragaria, being that this genus presents more than 45 described species, and only 11 are considered natural species. Due to the octoploid nature of strawberry and its variability after hybridization, selecting one or more characters may result in unfavorable genotypes and even the exclusion of promising ones, because negative genetic correlations have been observed among them that cause inefficient selection. Therefore, the objective of this study was to verify the efficiency of selection indices in selecting experimental strawberry hybrids for in natura consumption and processing. Seven commercial cultivars and 103 hybrids were used, which were obtained from populations derived from their crossings. The experiment was conducted in augmented blocks, in which four agronomical traits (total mass, amount of commercial fruit, amount of noncommercial fruit, and average fruit mass) and seven physical-chemical traits (soluble solids, soluble solids:titratable acidity ratio, total sugars, total pectin, vigor, and internal and external coloration) were evaluated. For hybrid selection, the following indices were used: Mulamba and Mock (1978), Smith (1936), Hazel (1943), and genotype-ideotype, which selected 20% of the genotypes evaluated. The three indices selected about 9% of the hybrids. The selection of two experimental hybrids (89 and 495) and the use of selection indices resulted in larger estimates of selection gains. The Mulamba and Mock (1978), Smith (1936), and Hazel (1943) indices had the highest percentage of gains on selection, and are therefore recommended for the selection of strawberry clones.

Resistance of upland-rice lines to root-knot nematode, Meloidogyne incognita.

Despite the benefits of crop rotation, occurrence of nematodes is a common problem for almost all crops within the Cerrado biome, especially for rice. The use of resistant cultivars is one of the main methods for control of nematodes. Thus, the present study aimed to evaluate the reaction of 36 upland-rice lines, with desirable agronomic characteristics, according to their resistance to root-knot nematodes (Meloidogyne incognita). The experimental design was entirely randomized with four replications. Each plot of land consisted of two rice plants in a 3-L vase. The plants were inoculated with 1000 eggs and eventual juveniles of the respective nematodes. Fifty-five days after the inoculation, the roots and the aerial part of the plant were weighed and the egg mass (EM) as well as the reproduction factor (Rf) were estimated. It was determined that the isolated use of EM was not beneficial in selecting rice lines resistant to the root-knot nematode. This procedure must, therefore, take into account the egg counting and the Rf, in order to improve the reliability of the selection. In our study, 30 evaluated lines were observed to be resistant. Among the recommended cultivars, only BRS Monarca had its performance susceptible to the studied nematode species.

Relationship of resting brain hyperconnectivity and schizophrenia-like symptoms produced by the NMDA receptor antagonist ketamine in humans.

N-methyl-D-aspartate glutamate receptor (NMDA-R) antagonists produce schizophrenia-like positive and negative symptoms in healthy human subjects. Preclinical research suggests that NMDA-R antagonists interfere with the function of gamma-aminobutyric acid (GABA) neurons and alter the brain oscillations. These changes have been hypothesized to contribute to psychosis. In this investigation, we evaluated the hypothesis that the NMDA-R antagonist ketamine produces alterations in cortical functional connectivity during rest that are related to symptoms. We administered ketamine to a primary sample of 22 subjects and to an additional, partially overlapping, sample of 12 subjects. Symptoms before and after the experimental session were rated with the Positive and Negative Syndrome Scale (PANSS). In the primary sample, functional connectivity was measured via functional magnetic resonance imaging almost immediately after infusion began. In the additional sample, this assessment was repeated after 45 min of continuous ketamine infusion. Global, enhanced functional connectivity was observed at both timepoints, and this hyperconnectivity was related to symptoms in a region-specific manner. This study supports the hypothesis that pathological increases in resting brain functional connectivity contribute to the emergence of positive and negative symptoms associated with schizophrenia.

Effect of slope on the forest structure of the Atlantic Forest domain in southern Brazil.

The mosaic landscape composition of forest fragments located on high slopes, shallow soils hinder ecological interactions and the survival of plant species. This study aimed to show, in an environment with these characteristics, the effect of the environmental gradient relating the soil, slope, and vegetation of a fragment of the Montane Seasonal Semideciduous Forest. The forest structure was sampled in 12 continuous rectangular plots, with 30 X 20m, totaling 0.72ha. Soil samples were taken by drilling every 20m along the hydrographic divisor and opening of three trenches used as soil sampling sites for in situ determination of soil color, horizon, and nutrients. Horizons were classified as O/A/Cr in the altered rock with a marked presence of gravels, and the soil was classified as Litholic Neosol. The area has a steep slope, from 18.05% to 36.99%. Linear regression analysis indicated an opposite pattern for species richness in relation to slope and a positive relationship between slope and the number of standing dead individuals. Species richness was also positively related to the distance from forest edges. The evaluation evidenced the strong influence of slope and human activities in forest remnant as common to several high-altitude remnants, and small conservation actions can guarantee their maintenance.

Antiproliferative, genotoxic and mutagenic potential of synthetic chocolate food flavoring.

Flavoring additives are of great technological importance for the food industry. However, there is little information regarding the toxicological properties of these micro-ingredients, especially at the cellular level. The present study used meristematic root cells of Allium cepa L. to evaluate the toxicity of a liquid, aroma and flavor synthetic chocolate additive, manufactured and widely marketed throughout Brazil and exported to other countries in South America. The flavoring concentrations evaluated were 100.00; 50.00; 25.00; 1.00; 0.50 and 0.25 µL/L, where the highest concentration established was one-hundred times lower than that commercially suggested for use. The concentration 100 µL/L substantially reduced cell division of meristems within 24- and 48-hours exposure. Concentrations from 100.00 to 0.50 µL/L resulted in a significant number of prophases to the detriment of the other phases of cell division, indicating an aneugenic activity, and induced a significant number of cellular changes, with emphasis on micronuclei, nuclear buds and chromosomal breaks. Under the established analysis conditions, with the exception of concentration 0.25 µL/L, the flavoring of chocolate caused cytotoxicity, genotoxicity and mutagenicity to root meristems.

Trends in systemic lupus erythematosus mortality rates in the state of Sao Paulo, Brazil from 1985 to 2004.

OBJECTIVES: To estimate mortality rates and mortality trends from SLE in the state of São Paulo, Brazil. MATERIAL AND METHODS: The official data bank was used to study all deaths occurred from 1985 to 2004 in which SLE was mentioned as the underlying cause of death. Besides the overall mortality rate, the annual gender- and age-specific mortality rates were estimated for each calendar year by age bracket (0-19 years, 20-39 years, 40-59 years and over 60 years) and for the sub-periods 1985-1995 (first) and 1996-2004 (second), by decades. Chi-square test was used to compare the mortality rates between the two periods, as well the mortality rates according to educational level considering years of study. Pearson correlation coefficient test was used to analyse mortality trends. The crude rates were adjusted for age by the direct method, using the standard Brazilian population in 2000. RESULTS: A total of 2,601 deaths (90% female) attributed to SLE were analysed. The mean age at death was significantly higher in the second than in the first sub-period (36.6+/-15.6 years vs. 33.9+/-14.0 years; p<0.001). The overall adjusted mortality rate was 3.8 deaths/million habitants/year for the entire period and 3.4 deaths/million inhabitants/year for the first and 4.0 deaths/million inhabitants/year for the second sub-period (p<0.001). In each calendar year, the mortality rate was significantly lower for the better educated group. Throughout the period, there was a significant increase in mortality rates only among women over 40. CONCLUSIONS: SLE patients living in the state of São Paulo still die at younger ages than those living in developed countries. Our data do not support the theory that there was an improvement in the SLE mortality rate in the last 20 years in the state of Sao Paulo. Socio-economic factors, such as the difficulty to get medical care and adequate treatment, may be the main factors to explain the worst prognosis for our patients.

Role of Synadenium grantii latex proteases in nematicidal activity on Meloidogyne incognita and Panagrellus redivivus.

Synadenium grantii is a Euphorbiaceae plant commonly found in Brazil, known as Janaúba or Leitosinha, whose latex is traditionally used for several purposes. However, it is not known whether the nematicidal action of this plant latex occurs due to the action of proteases. The present work aims to evaluate the nematicidal activity of proteases from Synadenium grantii latex on Meloidogyne incognita and Panagrellus redivivus. S. grantii latex used in the present study was collected from specimens found in Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil. The drained latex was collected in Eppendorf microtubes and immediately stored on ice at 4 °C. After this extraction, the latex was frozen (-20 °C) during 2 hours, thawed at room temperature (25 °C) and centrifuged at 10,000 g at 4 °C for 30 minutes to remove larger particles and concentrate the proteases. After the centrifugation, assays of enzymatic activity were performed in order to know in which of the phases the enzymes were found. S. grantii latex presented protease, but no chitinase activity. The results show that there was a significant difference (p <0.01) between the treated and control groups, with 100% mortality of Meloidogyne incognita and 72% average mortality of Panagrellus redivivus. In addition, it was demonstrated that the nematicidal action occurred due to the action of the proteases, since the control was only differentiated from the treatment by the presence of the enzymes with biological activity.

Ovulation synchronization with estradiol benzoate or GnRH in a timed artificial insemination protocol in buffalo cows and heifers during the nonbreeding season.

The aim of this study was to compare estradiol benzoate (EB) and GnRH for the induction of ovulation in a TAI protocol in buffalo during the nonbreeding season. In experiment 1, 141 buffaloes (56 cows and 85 heifers) received an intravaginal P4 device (1.0 g) plus EB (2.0-mg, intramuscular [im]) at random stage of the estrous cycle (Day 0). On Day 9, the P4 device was removed, and buffaloes were given PGF2α (0.53-mg im sodium cloprostenol) plus eCG (400-IU im). Buffaloes were then randomly allocated to one of three groups and treated as follows: EB24 (n = 47), EB (1.0 mg im) 24 hours after P4 device removal; EB36 (n = 50), EB 36 hours after P4 device removal; GnRH48 (n = 44), GnRH (10 µg im buserelin acetate) 48 hours after P4 device removal. Ultrasound examinations were performed on Day 0 to ascertain ovarian follicular status, Day 9 to measure follicular diameter, and from Day 11 to Day 14 (every 12 hours for 60 hours) to establish the time of ovulation. There were no significant differences between EB24, EB36, and GnRH48 for diameter of the ovulatory follicle (13.1 ± 0.3, 13.7 ± 0.3, and 13.7 ± 0.3 mm; P = 0.26) and ovulation rate (78.7%, 82.0%, and 84.1%; P = 0.93). When compared with heifers, cows had a greater diameter of the dominant follicle on Day 9 (10.3 ± 0.3 and 8.6 ± 0.2 mm; P = 0.0001), diameter of the ovulatory follicle (14.1 ± 0.3 and 13.1 ± 0.2 mm; P = 0.01), ovulation rate (91.1% and 75.3%; P = 0.02), and interval from P4 device removal to ovulation (76.3 ± 1.3 and 72.5 ± 1.4 hours; P = 0.05). In experiment 2, 511 buffaloes (354 cows and 157 heifers) were assigned to the same treatments described in experiment 1 (EB24, n = 168; EB36, n = 172; and GnRH48, n = 171), and all animals were submitted to timed artificial insemination (TAI) 64 hours after P4 device removal. Pregnancy diagnosis was undertaken 30 days after TAI. There were no significant differences between EB24, EB36, and GnRH48 for pregnancy rate (45.2%, 43.0%, and 49.7%; P = 0.46), and the pregnancy rate did not differ (P = 0.31) for cows (47.5%) and heifers (42.7%). The findings from the two experiments indicated that EB (24 or 36 hours) and GnRH (48 hours) induce comparable follicular responses, ovulation, and pregnancy rates in buffalo cows and heifers. Although there were some differences in the follicular responses between cows and heifers, the pregnancy rate to TAI was nonetheless similar.

Antiproliferative, genotoxic and mutagenic potential of synthetic chocolate food flavoring / Potencial antiproliferativo, genotóxico e mutagênico do aroma de chocolate sintético para alimentos

Flavoring additives are of great technological importance for the food industry. However, there is little information regarding the toxicological properties of these micro-ingredients, especially at the cellular level. The present study used meristematic root cells of Allium cepa L. to evaluate the toxicity of a liquid, aroma and flavor synthetic chocolate additive, manufactured and widely marketed throughout Brazil and exported to other countries in South America. The flavoring concentrations evaluated were 100.00; 50.00; 25.00; 1.00; 0.50 and 0.25 µL/L, where the highest concentration established was one-hundred times lower than that commercially suggested for use. The concentration 100 µL/L substantially reduced cell division of meristems within 24- and 48-hours exposure. Concentrations from 100.00 to 0.50 µL/L resulted in a significant number of prophases to the detriment of the other phases of cell division, indicating an aneugenic activity, and induced a significant number of cellular changes, with emphasis on micronuclei, nuclear buds and chromosomal breaks. Under the established analysis conditions, with the exception of concentration 0.25 µL/L, the flavoring of chocolate caused cytotoxicity, genotoxicity and mutagenicity to root meristems.

Os aditivos aromatizantes têm grande importância tecnológica para a indústria de alimentos. Contudo, poucas são as informações quanto as propriedades toxicológicas desses microingredientes, especialmente, em nível celular. No presente estudo avaliou-se, sobre as células meristemáticas de raízes de Allium cepa L., a toxicidade de um aditivo sintético líquido de aroma e sabor de chocolate, fabricado e amplamente comercializado em todo Brasil, e exportado para outros países da América do Sul. As concentrações de aromatizante avaliadas foram 100,00; 50,00; 25,00; 1,00; 0,50 e 0,25 µL/L, onde a maior concentração estabelecida foi cem vezes menor que a sugerida comercialmente para uso. Com base na interpretação dos resultados, a concentração 100 µL/L reduziu substancialmente a divisão celular dos meristemas nas 24 e 48 horas de exposição. As concentrações 100,00 a 0,50 µL/L demonstraram número significativo de prófases em detrimento as outras fases da divisão celular, indicando ação aneugênica, e induziram número significativo de alterações celulares, com ênfase a micronúcleos, broto nucleares e quebras cromossômicas. Nas condições de análises estabelecidas, com exceção a concentração 0,25 µL/L, o aromatizante de chocolate causou citotoxicidade, genotoxicidade e mutagenicidade aos meristemas radiculares.

Antiproliferative, genotoxic and mutagenic potential of synthetic chocolate food flavoring

Abstract Flavoring additives are of great technological importance for the food industry. However, there is little information regarding the toxicological properties of these micro-ingredients, especially at the cellular level. The present study used meristematic root cells of Allium cepa L. to evaluate the toxicity of a liquid, aroma and flavor synthetic chocolate additive, manufactured and widely marketed throughout Brazil and exported to other countries in South America. The flavoring concentrations evaluated were 100.00; 50.00; 25.00; 1.00; 0.50 and 0.25 µL/L, where the highest concentration established was one-hundred times lower than that commercially suggested for use. The concentration 100 µL/L substantially reduced cell division of meristems within 24- and 48-hours exposure. Concentrations from 100.00 to 0.50 µL/L resulted in a significant number of prophases to the detriment of the other phases of cell division, indicating an aneugenic activity, and induced a significant number of cellular changes, with emphasis on micronuclei, nuclear buds and chromosomal breaks. Under the established analysis conditions, with the exception of concentration 0.25 µL/L, the flavoring of chocolate caused cytotoxicity, genotoxicity and mutagenicity to root meristems.

Resumo Os aditivos aromatizantes têm grande importância tecnológica para a indústria de alimentos. Contudo, poucas são as informações quanto as propriedades toxicológicas desses microingredientes, especialmente, em nível celular. No presente estudo avaliou-se, sobre as células meristemáticas de raízes de Allium cepa L., a toxicidade de um aditivo sintético líquido de aroma e sabor de chocolate, fabricado e amplamente comercializado em todo Brasil, e exportado para outros países da América do Sul. As concentrações de aromatizante avaliadas foram 100,00; 50,00; 25,00; 1,00; 0,50 e 0,25 µL/L, onde a maior concentração estabelecida foi cem vezes menor que a sugerida comercialmente para uso. Com base na interpretação dos resultados, a concentração 100 µL/L reduziu substancialmente a divisão celular dos meristemas nas 24 e 48 horas de exposição. As concentrações 100,00 a 0,50 µL/L demonstraram número significativo de prófases em detrimento as outras fases da divisão celular, indicando ação aneugênica, e induziram número significativo de alterações celulares, com ênfase a micronúcleos, broto nucleares e quebras cromossômicas. Nas condições de análises estabelecidas, com exceção a concentração 0,25 µL/L, o aromatizante de chocolate causou citotoxicidade, genotoxicidade e mutagenicidade aos meristemas radiculares.

Antiproliferative, genotoxic and mutagenic potential of synthetic chocolate food flavoring / Potencial antiproliferativo, genotóxico e mutagênico do aroma de chocolate sintético para alimentos

Flavoring additives are of great technological importance for the food industry. However, there is little information regarding the toxicological properties of these micro-ingredients, especially at the cellular level. The present study used meristematic root cells of Allium cepa L. to evaluate the toxicity of a liquid, aroma and flavor synthetic chocolate additive, manufactured and widely marketed throughout Brazil and exported to other countries in South America. The flavoring concentrations evaluated were 100.00; 50.00; 25.00; 1.00; 0.50 and 0.25 µL/L, where the highest concentration established was one-hundred times lower than that commercially suggested for use. The concentration 100 µL/L substantially reduced cell division of meristems within 24- and 48-hours exposure. Concentrations from 100.00 to 0.50 µL/L resulted in a significant number of prophases to the detriment of the other phases of cell division, indicating an aneugenic activity, and induced a significant number of cellular changes, with emphasis on micronuclei, nuclear buds and chromosomal breaks. Under the established analysis conditions, with the exception of concentration 0.25 µL/L, the flavoring of chocolate caused cytotoxicity, genotoxicity and mutagenicity to root meristems.

Os aditivos aromatizantes têm grande importância tecnológica para a indústria de alimentos. Contudo, poucas são as informações quanto as propriedades toxicológicas desses microingredientes, especialmente, em nível celular. No presente estudo avaliou-se, sobre as células meristemáticas de raízes de Allium cepa L., a toxicidade de um aditivo sintético líquido de aroma e sabor de chocolate, fabricado e amplamente comercializado em todo Brasil, e exportado para outros países da América do Sul. As concentrações de aromatizante avaliadas foram 100,00; 50,00; 25,00; 1,00; 0,50 e 0,25 µL/L, onde a maior concentração estabelecida foi cem vezes menor que a sugerida comercialmente para uso. Com base na interpretação dos resultados, a concentração 100 µL/L reduziu substancialmente a divisão celular dos meristemas nas 24 e 48 horas de exposição. As concentrações 100,00 a 0,50 µL/L demonstraram número significativo de prófases em detrimento as outras fases da divisão celular, indicando ação aneugênica, e induziram número significativo de alterações celulares, com ênfase a micronúcleos, broto nucleares e quebras cromossômicas. Nas condições de análises estabelecidas, com exceção a concentração 0,25 µL/L, o aromatizante de chocolate causou citotoxicidade, genotoxicidade e mutagenicidade aos meristemas radiculares.

Cannabis-associated psychosis: Neural substrate and clinical impact.

Prospective epidemiological studies have consistently demonstrated that cannabis use is associated with an increased subsequent risk of both psychotic symptoms and schizophrenia-like psychoses. Early onset of use, daily use of high-potency cannabis, and synthetic cannabinoids carry the greatest risk. The risk-increasing effects are not explained by shared genetic predisposition between schizophrenia and cannabis use. Experimental studies in healthy humans show that cannabis and its active ingredient, delta-9-tetrahydrocannabinol (THC), can produce transient, dose-dependent, psychotic symptoms, as well as an array of psychosis-relevant behavioral, cognitive and psychophysiological effects; the psychotogenic effects can be ameliorated by cannabidiol (CBD). Findings from structural imaging studies in cannabis users have been inconsistent but functional MRI studies have linked the psychotomimetic and cognitive effects of THC to activation in brain regions implicated in psychosis. Human PET studies have shown that acute administration of THC weakly releases dopamine in the striatum but that chronic users are characterised by low striatal dopamine. We are beginning to understand how cannabis use impacts on the endocannabinoid system but there is much still to learn about the biological mechanisms underlying how cannabis increases risk of psychosis. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".

Patterns of the aquatic macrophyte cover in Cachoeira Dourada Reservoir (GO-MG).

The relationship between the aquatic macrophyte cover in upper segments of tributaries and this cover in these tributaries but near the reservoir's main body was tested. Sixteen taxa belonging to 12 families of aquatic macrophytes were recorded in Cachoeira Dourada Reservoir. The most frequent species were Eichhornia azurea (frequency of occurrence=92%; n=37 sites) and E. crassipes (44%). Upper segments of the tributaries were the main areas colonized by these aquatic macrophytes. The positive relationship between the aquatic macrophyte cover between the upper and lower segments of tributaries indicates the importance of dispersion in the colonization of the arms and the reservoir's main body.

Water level effect on herbaceous plant assemblages at an artificial reservoir-Lago Azul State Park, Southern Brazil.

This study presents the effect of water level variation on the assemblages of herbaceous species in Mourão I Reservoir, Lago Azul State Park, Southern Brazil. The structure and distribution of populations was examined in February (dry period) and April (rainy period), 2011, in two transects. These transects started at the forest edge towards the center of the lake. The end of the transect coincided with the end of the plants within the lake. On every two meters along of the transects we sampled a wooden square of 0.25 m(2) for species biomass analysis.The macrophyte stand was composed entirely of emergent species. Considering the periods, most species were less frequent in the rainy period (April), but Ipomea ramosissima (Poir.) Choisy, Commelina nudiflora L., Eleocharis acuntagula (Roxb.) Schult. and Verbena litorales (Kunth.) had their frequency increased during this period, probably due to their resistance. The influence of flood as measured by the NMDS point out that both before and after the flood, there are plots with distinct compositions and biomass. The water level variation affects the dynamics of plant composition and structure in marginal areas of the Reservoir.

Influence of urban area on the water quality of the Campo River basin, Paraná State, Brazil.

The Campo River basin is located on the third plateau of the Paraná State or trap plateau of Paraná, at the middle portion between the rivers Ivaí and Piquiri, southern Brazil, between the coordinates 23° 53 and 24° 10' South Latitude and 52° 15' and 52° 31' West Longitude. The basin has 384 Km² area, being 247 km² in the municipality of Campo Mourão and 137 km² in the municipality of Peabiru, in Paraná State. The Campo River is a left bank tributary of the Mourão River, which flows into the Ivaí River. The objective of this study was to monitor water quality in the Km 119 River and the Campo River, tributaries of the Mourão River, with monthly collection of water samples to determine pH, temperature, turbidity, biochemical oxygen demand, dissolved oxygen, fecal coliforms, total solids, total nitrogen, ammoniacal nitrogen, nitrite, nitrate and total phosphorus. The results obtained were compared with the indices established by the environmental legislation and applied in the determination of the Water Quality Index (WQI) used by the Water Institute of Paraná State, regulating environmental agency. Poor water quality in these rivers presents a worrying scenario for the region, since this river is the main source of water supply for the public system. Results of organic matter, fecal coliforms and total phosphorus were higher than the limits established by Resolution CONAMA 357/2005 to river class 2, specially at downstream of the Km 119 River and the Campo River, due to the significant influence of the urban anthropic activity by the lack of tertiary treatment and also rural by the lack of basic sanitation in this area. Results of WQI of Km 119 River and do Campo River indicated that water quality can be classified as average in 71% and good in 29% of the sites evaluated.

Symptom provocation studies in psychiatric disorders: scientific value, risks, and future.

Several lines of investigation have contributed to the increasing recognition of the biological basis of psychiatric disorders. Symptom provocation studies have made important contributions toward this. With the emergence of novel methodologies, the role of symptom provocation studies has come under increasing scrutiny and debate. The scientific contributions and risks of symptom provocation studies are discussed using the psychostimulant paradigm in schizophrenia research as the prototypical study. The application of studies in other areas of medicine that carry risks similar to those associated with symptom provocation studies, are also reviewed. The authors draw on the parallel of cardiac stress testing to highlight risks: benefits issues. Finally, the authors discuss the future of symptom provocation studies and emphasize that these studies will need to meet the highest scientific standards, ethical standards and safeguards.

Dopamine and serotonin transporters in patients with schizophrenia: an imaging study with [(123)I]beta-CIT.

BACKGROUND: Several lines of evidence derived from imaging and postmortem studies suggest that schizophrenia is associated with hyperactivity of dopamine function and deficiency in serotonin (5-HT) function. The aim of this study was to investigate potential alterations of striatal dopamine transporters (DAT) and brainstem serotonin transporters (SERT) density in schizophrenia. METHODS: Striatal DAT and brainstem SERT were measured in 24 patients with schizophrenia and 22 matched healthy control subjects using single photon emission computed tomography and [(123)I]beta-CIT. In this cohort of subjects, we previously reported an increase in striatal amphetamine-induced dopamine release, measured as the displacement of the D(2) receptor radiotracer [(123)I]IBZM. RESULTS: No differences were observed between patients and control subjects in the equilibrium uptake ratio (V(3)") of [(123)I]beta-CIT in the striatum, indicating that schizophrenia is not generally associated with an alteration of striatal DAT density; however, a trend level association (p =.07) was observed in patients with schizophrenia between low striatal [(123)I]beta-CIT V(3)" and severity of negative symptoms. After controlling for age, striatal [(123)I]beta-CIT V(3)" in patients was not associated with duration of illness, suggesting that this relative deficit was not secondary to a neurodegenerative process. No correlation was observed between DAT density and amphetamine-induced dopamine release, either in the patients or in the controls. Brainstem [(123)I]beta-CIT V(3)" was unaffected in patients with schizophrenia, and was unrelated to symptomatology. CONCLUSIONS: Schizophrenia is generally not associated with alterations of DAT in the striatum or SERT in the brainstem. In some patients, a relative deficit in dopamine nerve terminals might play a role in the pathophysiology of negative symptoms.