Efeito da densidade do solo na incidência de Fusarium spp.

O objetivo deste trabalho foi avaliar o efeito da densidade do solo resultante de dois sistemas de manejo e seis rotações de culturas na população de Fusarium spp

Efeito de rotações de cultura sobre populações de microorganismos do solo.

A rotação de culturas afeta diretamente a diversidade e densidade de microrganismos sobreviventes no solo, entre os quais destacam-se patógenos e agentes de controle biológico

Epigenetic-mediated N -methyl-D-aspartate receptor changes in the brain of isolated reared rats

Aim: We investigated: Grin1, Grin2a, Grin2b DNA methylation; NR1 and NR2 mRNA/protein in the prefrontal cortex (PFC); and hippocampus of male Wistar rats exposed to isolation rearing. Materials & methods: Animals were kept isolated or grouped (n = 10/group) from weaning for 10 weeks. Tissues were dissected for RNA/DNA extraction and N-methyl-D-aspartate receptor subunits were analyzed using quantitative reverse transcription (RT)-PCR, ELISA and pyrosequencing. Results: Isolated-reared animals had: decreased mRNA in PFC for all markers, increased NR1 protein in hippocampus and hypermethylation of Grin1 in PFC and Grin2b in hippocampus, compared with grouped rats. Associations between mRNA/protein and DNA methylation were found for both brain areas. Conclusion: This study indicates that epigenetic DNA methylation may underlie N-methyl-D-aspartate receptor mRNA/protein expression alterations caused by isolation rearing

Gene and environmental risk factors: interplay between CNR1 genetic variants cannabis use, childhood trauma and psychosis [abstract only]

Background: Cannabis use and childhood trauma have been proposed as environmental risk factors for psychosis and its known that gene-environment (G×E) interactions increase the risk of psychosis [1]. In particular, a recent finding suggests a link between genetic variants in the cannabinoid receptor type 1 (CNR1) gene, which encodes CB1 receptors and is expressed widely in the central and peripheral systems, and cannabis playing a role in the multifactorial pathogenesis of psychosis [2]. However, how the genetic variants interact with lifetime cannabis use and other environmental risk factors, such as childhood trauma, underlying psychosis remains challenging. Objective: To investigate whether there are associations of gene and environmental factors with psychosis, as well as G×E interactions in the relationship between lifetime cannabis use, childhood trauma, and single nucleotide variants (SNVs) of CNR1 and psychosis in a Brazilian sample. Methods: In a population-based case-control study nested in an incident study (STREAM, Brazil) [3], part of the WP2 EU-GEI consortium, 143 first-episode psychosis patients (FEPp) and 286 community-based controls of both sexes, aged between 16 and 64 years, were included over a period of three years. Thirteen SNVs of CNR1 gene (rs806380, rs806379, rs1049353, rs6454674, rs1535255, rs2023239, rs12720071, rs6928499, rs806374, rs7766029, rs806378, rs10485170, rs9450898), were genotyped from peripheral blood DNA using a custom Illumina HumanCoreExome-24 BeadChip genotyping arrays (GWAS Cardiff chip). Environmental adversities were evaluated using the Cannabis Experience and the Childhood Trauma Questionnaires. Data were analysed using a binary logistic regression model (Adj OR, 95% CI), including a binary outcome (community-based controls and FEPp), adjusted by sex, age, skin colour, years of education and tobacco smoking. Genotype frequencies were analysed under the dominant model (homozygous ancestral x heterozygous + homozygous variant). The significance level was set at α≤0.05. Results: Lifetime cannabis use and childhood trauma increased the risk for psychosis (OR=3.7; 2.6-6.195% CI, p<0.001; OR=3.0; 1.9-4.7 95% CI, p<0.001, respectively). We also showed that the presence of CNR1 rs12720071-T-allele moderated the association between lifetime cannabis use and psychosis (OR=6.0; 2.0-17.5 95% CI; p=0.001). Moreover, the combination of CNR1 rs12720071-T-allele carriers with childhood trauma also suggests a change in the risk of psychosis (OR=3.6; 1.4-9.0 95% CI; p=0.006). No significant associations between the environmental factors and other SNVs were found. Conclusions: We demonstrated a significant interaction between CNR1 rs12720071 SNV and two important environmental risk factors in their association with psychosis. T allele carriers of CNR1 rs12720071 had a higher risk of psychosis when lifetime cannabis use or childhood trauma were present. Our results suggest a G×E interaction involving the CNR1 gene, trauma and cannabis in psychosis. We will explore the associations between genetic and epigenetic markers of the CNR1 gene with environmental factors in larger and longer follow-up cohorts to better understand the mechanisms of endocannabinoid system dysfunction in the etiology of psychosis

Effect of D2R, NMDAR and CB1R genetic variants associated with cannabis use and childhood trauma in first-episode psychosis in a Brazilian population [abstract only]

Introduction Gene-environment interactions increase psychosis risk (Gayer-Anderson et al. Soc Psychiatry Psychiatr Epidemiol 2020; 55(5):645-657). However, identifying the genetic variants involved and how they interact with environmental risk factors underlying psychosis remains challenging. Objectives To investigate whether there are gene-environment interactions in the relationships of childhood trauma, lifetime cannabis use, and single nucleotide variants (SNVs) of dopamine D2 receptor (D2R: DRD2), N-methyl-d-aspartate receptor (NMDAR: GRIN1, GRIN2A and GRIN2B) and cannabinoid receptor type 1 (CB1R: CNR1) with psychosis. Methods In a population-based case-control study nested in an incident study (STREAM, Brazil) (Del-Ben et al. Br J of Psychiatry 2019; 215(6):726-729), part of the EU-GEI consortium (Gayer-Anderson et al. Soc Psychiatry Psychiatr Epidemiol 2020; 55(5):645-657), 143 first-episode psychosis patients and 286 community-based controls of both sexes aged between 16 and 64 years were included over a period of 3 years. Twenty-three SNVs of D2R (rs1799978, rs7131056, rs6275), NMDAR (GRIN1: rs4880213, rs11146020; GRIN2A: rs1420040, rs11866328; GRIN2B: rs890, rs2098469, rs7298664), and CB1R genes (CNR1: rs806380, rs806379, rs1049353, rs6454674, rs1535255, rs2023239, rs12720071, rs6928499, rs806374, rs7766029, rs806378, rs10485170, rs9450898), were genotyped from peripheral blood DNA using a custom Illumina HumanCoreExome-24 BeadChip. Environmental adversities were evaluated using the Cannabis Experience Questionnaire (Di Forti et al. The Lancet Psychiatry 2009; 6(5):427–436) and the Childhood Trauma Questionnaire (Grassi-Oliveira et al. Rev Saude Publica 2006; 40(2):249-55). Associations between SNVs and environmental risk factors were performed using the nonparametric multifactor dimensionality reduction software (version 3.0.2). Results Single locus analysis showed no association among the 23 SNVs with psychosis; however, gene-environment analysis was significant for the polymorphic loci rs12720071 and rs7766029 in CNR1. The best association models were the two-factor representing by the combination of CNR1 rs12720071 with lifetime cannabis use (p<0.001), and CNR1 rs12720071 with childhood trauma (p<0.05), both suggesting an increased risk of psychosis. Additionally, when considering the interaction of both environmental factors in the same model, we found CNR1 rs7766029 to be associated with psychosis (p<0.001). Conclusions Our study supports the hypothesis of gene-environment interactions for psychosis involving the T allele carriers of CNR1 SNVs (rs12720071 and rs7766029), childhood trauma and lifetime cannabis use in psychosis

Lifetime cannabis use and childhood trauma associated with CNR1 genetic variants increase the risk of psychosis: findings from the STREAM study

Objectives: Gene-environment interactions increase the risk of psychosis. The objective of this study was to investigate gene-gene and gene-environment interactions in psychosis, including single nucleotide variants (SNVs) of dopamine-2 receptor (D2R), N-methyl-d-aspartate receptor (NMDAR), and cannabinoid receptor type 1 (CB1R), lifetime cannabis use, and childhood trauma. Methods: Twenty-three SNVs of genes encoding D2R (DRD2: rs1799978, rs7131056, rs6275), NMDAR (GRIN1: rs4880213, rs11146020; GRIN2A: rs1420040, rs11866328; GRIN2B: rs890, rs2098469, rs7298664), and CB1R (CNR1: rs806380, rs806379, rs1049353, rs6454674, rs1535255, rs2023239, rs12720071, rs6928499, rs806374, rs7766029, rs806378, rs10485170, rs9450898) were genotyped in 143 first-episode psychosis patients (FEPp) and 286 communitybased controls by Illumina HumanCoreExome-24 BeadChip. Gene-gene and gene-environment associations were assessed using nonparametric Multifactor Dimensionality Reduction software. Results: Single-locus analyses among the 23 SNVs for psychosis and gene-gene interactions were not significant (p 4 0.05 for all comparisons); however, both environmental risk factors showed an association with psychosis (p o 0.001). Moreover, gene-environment interactions were significant for an SNV in CNR1 and cannabis use. The best-performing model was the combination of CNR1 rs12720071 and lifetime cannabis use (p o 0.001), suggesting an increased risk of psychosis. Conclusion: Our study supports the hypothesis of gene-environment interactions for psychosis involving T-allele carriers of CNR1 SNVs, childhood trauma, and cannabis use

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable amazon network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazônia Sustentável, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far