RESUMO
Exopolymeric substances (EPS) as an external matrix of biofilm could react with disinfectants in drinking water networks forming disinfection by-products (DBP). Based on an experimental setup using two chlorine conditions-biofilm 1 (2.6 ± 0.8 mgCl/L) and biofilm 2 (0.7 ± 0.2 mg Cl/L)-samples of biofilms were recovered during 9 campaigns and EPS were extracted. Analyses of SUVA, fluorescence and amino acid (AA) content were carried out on the EPS to observe variation over time and correlations with DBP formation potential (DBPfp) after chlorination. SUVA values were under 2 L/mgC*m showing that both EPS were hydrophilic. Slightly higher SUVA in biofilm 2 with low variation over time was observed. Fluorescence showed that aromatic proteins and fulvic like substances were the principal components and increased in biofilm 1 over time. AA decreased with time, and higher values of alanine, threonine, proline and isoleucine were observed in biofilm 2. Based on general associations, the SUVA of biofilm 2 correlated well with chloroform (CF) (r = 0.80). Generally, in both biofilms, tryptophan-like substances were negatively correlated with DBP while humic acid-like substances correlated positively, but with low indexes (r = 0.3-0.6). Correlations of data from individual sampling increased the indices (r over 0.8), suggesting a temporal influence of other factors on DBPfp such as inorganics, filtered water and the structural composition of EPS. In biofilm 1, Br-haloacetic acids (Br-HAA), dibromoacetonitrile and bromochloro acetonitrile were inversely associated with arginine and valine, as were di and trichloropropanone to arginine. On the contrary, in biofilm 2, the following amino acids correlated positively with DBP: alanine with Br-HAA, alanine with CF, alanine with N-DBP (chloropicrin, di and tri-chloro acetonitrile), and valine with CF. As this is the first report about the relation between temporal variation of EPS and DBPfp of biofilms in two different chlorinated conditions, it provides new evidence about the function of these complex substances in drinking water systems.
Assuntos
Desinfecção , Água Potável/química , Biofilmes , Cloro , Desinfetantes/metabolismo , Purificação da ÁguaRESUMO
Iron is an essential micronutrient for plants. Little is know about how iron is loaded in embryo during seed development. In this article we used Perls/DAB staining in order to reveal iron localization at the cellular and subcellular levels in different Brassicaceae seed species. In dry seeds of Brassica napus, Nasturtium officinale, Lepidium sativum, Camelina sativa, and Brassica oleracea iron localizes in vacuoles of cells surrounding provasculature in cotyledons and hypocotyl. Using B. napus and N. officinale as model plants we determined where iron localizes during seed development. Our results indicate that iron is not detectable by Perls/DAB staining in heart stage embryo cells. Interestingly, at torpedo development stage iron localizes in nuclei of different cells type, including integument, free cell endosperm and almost all embryo cells. Later, iron is detected in cytoplasmic structures in different embryo cell types. Our results indicate that iron accumulates in nuclei in specific stages of embryo maturation before to be localized in vacuoles of cells surrounding provasculature in mature seeds.
RESUMO
A single exposure to amphetamine induces neurochemical sensitization in striatal areas. The neuropeptide angiotensin II, through AT1 receptors (AT1-R) activation, is involved in these responses. However, amphetamine-induced alterations can be extended to extra-striatal areas involved in blood pressure control and their physiological outcomes. Our aim for the present study was to analyze the possible role for AT1-R in these events using a two-injection protocol and to further characterize the proposed AT1-R antagonism protocol. Central effect of orally administered AT1-R blocker (Candesartan, 3mg/kg p.o.×5days) in male Wistar rats was analyzed by spontaneous activity of neurons within locus coeruleus. In another group of animals pretreated with the AT1-R blocker or vehicle, sensitization was achieved by a single administration of amphetamine (5mg/kg i.p. - day 6) followed by a 3-week period off drug. On day 27, after receiving an amphetamine challenge (0.5mg/kg i.p.), we evaluated: (1) the sensitized c-Fos expression in locus coeruleus (LC), nucleus of the solitary tract (NTS), caudal ventrolateral medulla (A1) and central amygdala (CeAmy); and (2) the blood pressure response. AT1-R blockade decreased LC neurons' spontaneous firing rate. Moreover, sensitized c-Fos immunoreactivity in TH+neurons was found in LC and NTS; and both responses were blunted by the AT1-R blocker pretreatment. Meanwhile, no differences were found neither in CeAmy nor A1. Sensitized blood pressure response was observed as sustained changes in mean arterial pressure and was effectively prevented by AT1-R blockade. Our results extend AT1-R role in amphetamine-induced sensitization over noradrenergic nuclei and their cardiovascular output.
Assuntos
Anfetamina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Receptor Tipo 1 de Angiotensina/metabolismo , Simpatomiméticos/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Pressão Sanguínea/fisiologia , Núcleo Central da Amígdala/citologia , Núcleo Central da Amígdala/efeitos dos fármacos , Núcleo Central da Amígdala/metabolismo , Locus Cerúleo/citologia , Locus Cerúleo/efeitos dos fármacos , Locus Cerúleo/metabolismo , Masculino , Bulbo/citologia , Bulbo/efeitos dos fármacos , Bulbo/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Distribuição Aleatória , Ratos Wistar , Núcleo Solitário/citologia , Núcleo Solitário/efeitos dos fármacos , Núcleo Solitário/metabolismoRESUMO
Pilosocereus machrisii and P. aurisetus are cactus species within the P. aurisetus complex, a group of eight cacti that are restricted to rocky habitats within the Neotropical savannas of eastern South America. Previous studies have suggested that diversification within this complex was driven by distributional fragmentation, isolation leading to allopatric differentiation, and secondary contact among divergent lineages. These events have been associated with Quaternary climatic cycles, leading to the hypothesis that the xerophytic vegetation patches which presently harbor these populations operate as refugia during the current interglacial. However, owing to limitations of the standard phylogeographic approaches used in these studies, this hypothesis was not explicitly tested. Here we use Approximate Bayesian Computation to refine the previous inferences and test the role of different events in the diversification of two species within P. aurisetus group. We used molecular data from chloroplast DNA and simple sequence repeats loci of P. machrisii and P. aurisetus, the two species with broadest distribution in the complex, in order to test if the diversification in each species was driven mostly by vicariance or by long-dispersal events. We found that both species were affected primarily by vicariance, with a refuge model as the most likely scenario for P. aurisetus and a soft vicariance scenario most probable for P. machrisii. These results emphasize the importance of distributional fragmentation in these species, and add support to the hypothesis of long-term isolation in interglacial refugia previously proposed for the P. aurisetus species complex diversification.
Assuntos
Evolução Biológica , Cactaceae/genética , Genética Populacional , Filogeografia , Refúgio de Vida Selvagem , Teorema de Bayes , Cactaceae/classificação , Simulação por Computador , DNA de Cloroplastos/genética , DNA de Plantas/genética , Ecossistema , Repetições de Microssatélites , Modelos Genéticos , Dispersão Vegetal , Análise de Sequência de DNA , América do SulRESUMO
OBJECTIVE: The aim of this study was to assess the prevalence of congenital defects observed in patients with Prader-Willi syndrome (PWS) and to compare this prevalence with that described in the general population. In addition, these findings were correlated with the different etiologic subtypes. METHODS: A total of 180 children with PWS followed for 13 years were included in this study. Diagnosis was confirmed by the methylation test, and genetic subtypes were established by using fluorescence in situ hybridization or multiplex ligation-dependent probe amplification and microsatellite analyses. The prevalence of congenital defects was compared with national and international registries of congenital defects in the general population (Estudio Colaborativo Latinoamericano de Malformaciones Congénitas, European Surveillance of Congenital Anomalies, and the New York Registry). RESULTS: Twenty-two percent of the patients presented congenital defects with a risk of 5.4 to 18.7 times higher than that of the general population. The most frequent congenital defects were heart defects, renoureteral malformations, vertebral anomalies, hip dysplasia, clubfoot, and agenesis/hypoplasia of the corpus callosum. Each of these congenital defects was significantly more frequent in the children with PWS than in the general population. The congenital heart defects were more frequent in girls than in boys with PWS. No significant differences were found when the defects were correlated with the different etiologic subtypes. CONCLUSIONS: An increased prevalence of congenital defects was found in our PWS patients. This finding suggests the need for further studies in PWS children that allow physicians to detect the congenital defects found in this series and, thus, to anticipate complications, with the ultimate aim of enhancing the management of PWS patients.
Assuntos
Anormalidades Congênitas/epidemiologia , Síndrome de Prader-Willi/epidemiologia , Adolescente , Criança , Deleção Cromossômica , Cromossomos Humanos Par 15/genética , Estudos de Coortes , Comorbidade , Anormalidades Congênitas/diagnóstico , Anormalidades Congênitas/genética , Estudos Transversais , Feminino , Seguimentos , Expressão Gênica/genética , Impressão Genômica/genética , Genótipo , Humanos , Masculino , Fenótipo , Síndrome de Prader-Willi/diagnóstico , Síndrome de Prader-Willi/genética , Estudos Retrospectivos , Fatores Sexuais , Dissomia Uniparental/genéticaRESUMO
El diagnóstico es Pitiriasis liquenoide crónica
Assuntos
Humanos , Masculino , Criança , Pitiríase Liquenoide/diagnóstico , Pitiríase Liquenoide/terapia , Argentina , Doença CrônicaRESUMO
A 13-amino acid peptide named neuronostatin (NST) encoded in the somatostatin pro-hormone has been recently reported. It is produced throughout the body, particularly in brain areas that have significant actions over the metabolic and autonomic regulation. The present study was performed in order to elucidate the functional role of NST on memory, anxiety-like behavior and food intake and the hippocampal participation in these effects. When the peptide was intra-hippocampally administered at 3.0 nmol/µl, it impaired memory retention in both, object recognition and step-down test. Also, this dose blocked the hippocampal long-term potentiation (LTP) generation. When NST was intra-hippocampally administered at 0.3 nmol/µl and 3.0 nmol/µl, anxiolytic effects were observed. Also, the administration in the third ventricle at the higher dose (3.0 nmol/µl) induced similar effects, and both doses reduced food intake. The main result of the present study is the relevance of the hippocampal formation in the behavioral effects induced by NST, and these effects could be associated to a reduced hippocampal synaptic plasticity.
Assuntos
Ansiedade/metabolismo , Ingestão de Alimentos/fisiologia , Hipocampo/metabolismo , Memória/fisiologia , Fragmentos de Peptídeos/metabolismo , Somatostatina/metabolismo , Animais , Ingestão de Alimentos/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/fisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Memória/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos WistarRESUMO
Hippocampus is a limbic structure that participates in learning and memory formation. Specifically the dentate gyrus has been described as a hippocampal subregion with high rates of plasticity and it is targeted by different psychoactive drugs modulating synaptic plasticity. Repeated cocaine administration induces sensitization to the locomotor effects and it is believed that sensitization involves the same mechanisms of drug seeking and relapse. Although, the mechanisms underlying sensitization is not fully understood. In this work we investigated the impact of repeated intraperitoneal administration of cocaine (15 or 20 mg/kg/day along 5 or 15 days respectively; and 15 mg/kg/day along 5 day followed by a challenge dose after three days of withdrawal) on the dentate gyrus synaptic plasticity, differentiating between sensitized and nonsensitized rats. Furthermore, we correlated changes on the hippocampal synaptic plasticity to memory retention. Our results revealed that the prevalence of cocaine sensitization (around 50%) was identical in all protocols used. The results found in the threshold to generate LTP were similar for all protocols used, being the threshold values cocaine-treated groups (sensitized and nonsensitized) significantly reduced compared to controls, observing the highest reduction in the sensitized group. Moreover, we observed a facilitated retention of recent memory formation only in sensitized animals the nonsensitized subjects remained at the control levels. In conclusion, sensitization to cocaine generates a high efficiency of hippocampal synaptic plasticity that may underlie the aberrant engagement of learning processes occurred during drug addiction.
Assuntos
Anestésicos Locais/efeitos adversos , Cocaína/efeitos adversos , Giro Denteado/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Análise de Variância , Animais , Comportamento Animal/efeitos dos fármacos , Biofísica , Distribuição de Qui-Quadrado , Relação Dose-Resposta a Droga , Esquema de Medicação , Estimulação Elétrica/métodos , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Técnicas In Vitro , Potenciação de Longa Duração/fisiologia , Masculino , Atividade Motora/fisiologia , Técnicas de Patch-Clamp , Desempenho Psicomotor/fisiologia , Ratos , Ratos Wistar , Estatística como AssuntoRESUMO
Benzodiazepines are commonly prescribed for the therapy of disorders such as anxiety and sleep disturbance, but develop dependence in many patients. In this review we discuss the impact of different brain areas that modulate the reward system in the development of tolerance and dependence to benzodiazepine and the associative processes underlying those fenomena.