RESUMO
Use of pesticides in agroecosystems is considered a major cause of bees diversity losses in the Neotropics, where Plebeia emerina (Friese) and Tetragonisca fiebrigi (Schwarz) (Hymenoptera: Apidae: Meliponini) are wild pollinators of native and crop plants. The aim of this study was to know the acute lethal toxicity of acetamiprid, malathion, phosmet and spinosad insecticides on P. emerina and T. fiebrigi. We obtained the mean concentration and mean lethal dose (LC50 and LD50) and the mean survival of workers after oral and topical exposure to insecticides, respectively. The LC50 values (ng a.i./µl of diet) and the decreasing order of toxicity for P. emerina was spinosad (4.96) > malathion (18.75) > phosmet (97.33) > acetamiprid (4204.06), and for T. fiebrigi also was spinosad (5.65) > malathion (8.39) > phosmet (53.91) > acetamiprid (9841.32), when orally exposed. The LD50 values (ng a.i./bee) and the decreasing order of toxicity for P. emerina was spinosad (1.90) > malathion (10.90) > phosmet (19.54) > acetamiprid (6216.55) and for T. fiebrigi was malathion (29.29) ≥ spinosad (29.79) > phosmet (41.95) > acetamiprid (1421.23), when topically exposed. The mean survival (hours) of contaminated bees by malathion, phosmet, and spinosad, was 11.81, 7.20, and 12.32 for P. emerina and 8.55, 7.20, and 13.34 for T. fiebrigi when orally exposed; and was 4.87, 9.87 and 11.17 for P. emerina, and 4.87, 4.76, and 19.05 for T. fiebrigi when topically exposed. Malathion, phosmet, and spinosad were highly toxic, while acetamiprid was moderately toxic. Our results indicated that the insecticides tested, mainly malathion, phosmet, and spinosad may be harmful to P. emerina and T. fiebrigi, making it essential to propose measures to minimize their impact on wild pollinators.
Assuntos
Abelhas/fisiologia , Himenópteros/fisiologia , Inseticidas/toxicidade , Animais , Abelhas/efeitos dos fármacos , Combinação de Medicamentos , Himenópteros/efeitos dos fármacos , Dose Letal Mediana , Macrolídeos , Malation , Neonicotinoides , PolinizaçãoRESUMO
Trichogin GA IV (GAIV) is an antimicrobial peptide of the peptaibol family, like the extensively studied alamethicin (Alm). GAIV acts by perturbing membrane permeability. Previous data have shown that pore formation is related to GAIV aggregation and insertion in the hydrophobic core of the membrane. This behavior is similar to that of Alm and in agreement with a barrel-stave mechanism, in which transmembrane oriented peptides aggregate to form a channel. However, while the 19-amino acid long Alm has a length comparable to the membrane thickness, GAIV comprises only 10 amino acids, and its helix is about half the normal bilayer thickness. Here, we report the results of neutron reflectivity measurements, showing that GAIV inserts in the hydrophobic region of the membrane, causing a significant thinning of the bilayer. Molecular dynamics simulations of GAIV/membrane systems were also performed. For these studies we developed a novel approach for constructing the initial configuration, by embedding the short peptide in the hydrophobic core of the bilayer. These calculations indicated that in the transmembrane orientation GAIV interacts strongly with the polar phospholipid headgroups, drawing them towards its N- and C-termini, inducing membrane thinning and becoming able to span the bilayer. Finally, vesicle leakage experiments demonstrated that GAIV activity is significantly higher with thinner membranes, becoming similar to that of Alm when the bilayer thickness is comparable to its size. Overall, these data indicate that a barrel-stave mechanism of pore formation might be possible for GAIV and for similarly short peptaibols despite their relatively small size.
Assuntos
Membrana Celular/metabolismo , Lipopeptídeos/química , Peptídeos/química , Aminoácidos/química , Biofísica/métodos , Membrana Celular/química , Simulação por Computador , Relação Dose-Resposta a Droga , Interações Hidrofóbicas e Hidrofílicas , Bicamadas Lipídicas/química , Lipídeos de Membrana/química , Conformação Molecular , Simulação de Dinâmica Molecular , Nanopartículas , Nêutrons , Estrutura Terciária de ProteínaRESUMO
Understanding how variations in genetic sequences are conveyed into structural and biochemical properties is of increasing interest in the field of molecular evolution. In order to gain insight into this process, we studied the ecdysone receptor (EcR), a transcription factor that controls moulting and metamorphosis in arthropods. Using an in silico homology model, we identified a region in the lepidopteran EcR that has no direct interaction with the natural hormone but is under strong evolutionary constraint. This region causes a small indentation in the three-dimensional structure of the protein which facilitates the binding of tebufenozide. Non-Mecopterida are considered much older, evolutionarily, than Lepidoptera and they do not have this extended cavity. This location shows differences in evolutionary constraint between Lepidoptera and other insects, where a much lower constraint is observed compared with the Lepidoptera. It is possible that the higher flexibility seen in the EcR of Lepidoptera is an entirely new trait and the higher constraint could then be an indication that this region does have another important function. Finally, we suggest that Try123, which is evolutionarily constrained and is up to now exclusively present in Lepidoptera EcRs, could play a critical role in discriminating between steroidal and non-steroidal ligands.
Assuntos
Benzamidas/metabolismo , Evolução Molecular , Hidrazinas/metabolismo , Inseticidas/metabolismo , Receptores de Esteroides/metabolismo , Tribolium/metabolismo , Sequência de Aminoácidos , Animais , Ligantes , Dados de Sequência Molecular , Filogenia , Alinhamento de SequênciaRESUMO
Carvacrol is the major constituent of essential oils from aromatic plants. It showed antimicrobial, anticancer and antioxidant properties. Although it was approved for food use and included in the chemical flavorings list, no indication on its safety has been estimated. Since the use of plant extracts is relatively high among women, aim of this study was to evaluate carvacrol effects on female physiology and endocrine profiles by using female rats in proestrus and diestrus phases. Serotonin and metabolite tissue content in prefrontal cortex and nucleus accumbens, after carvacrol administration (0.15 and 0.45g/kg p.o.), was measured. Drug effects in behavioral tests for alterations in motor activity, depression, anxiety-related behaviors and endocrine alterations were also investigated. While in proestrus carvacrol reduced serotonin and metabolite levels in both brain areas, no effects were observed in diestrus phase. Only in proestrus phase, carvacrol induced a depressive-like behavior in forced swimming test, without accompanying changes in ambulation. The improvement of performance in FST after subchronic treatment with fluoxetine (20mg/kg) suggested a specific involvement of serotonergic system. No differences were found across the groups with regard to self-grooming behavior. Moreover, in proestrus phase, carvacrol reduced only estradiol levels without binding hypothalamic estradiol receptors. Our study showed an estrous-stage specific effect of carvacrol on depressive behaviors and endocrine parameters, involving serotonergic system. Given the wide carvacrol use not only as feed additive, but also as cosmetic essence and herbal remedy, our results suggest that an accurate investigation on the effects of its chronic exposure is warranted.
Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Ciclo Estral/fisiologia , Ácido Hidroxi-Indolacético/metabolismo , Monoterpenos/farmacologia , Serotonina/metabolismo , Animais , Cimenos , Depressão/induzido quimicamente , Depressão/metabolismo , Estradiol/sangue , Feminino , Asseio Animal/efeitos dos fármacos , Ácido Hidroxi-Indolacético/análise , Atividade Motora/efeitos dos fármacos , Progesterona/sangue , Ratos , Ratos Wistar , Serotonina/análise , NataçãoRESUMO
Insecticidal gene silencing by RNA interference (RNAi) involves a post-transcriptional mechanism with great potential for insect control. Here, we aim to summarize the progress on RNAi research toward control of insect pests in the Neotropical region and discuss factors determining its efficacy and prospects for pest management. We include an overview of the available RNAi information for Neotropical pests in the Lepidoptera, Coleoptera, Diptera, and Hemiptera orders. Emphasis is put on significant findings in the use of RNAi against relevant Neotropical pests, including diamondback moth (Plutella xylostella L.), Asian citrus psyllid (Diaphorina citri Kuwayama), and the cotton boll weevil (Anthonomus grandis Boheman). We also examine the main factors involved in insecticidal RNAi efficiency and major advances to improve screening of lethal genes, formulation, and delivery. Few studies detail resistance mechanisms to RNAi, demonstrating a need for more research. Advances in formulation, delivery, and resistance management tools for insecticidal RNAi in the Neotropics can provide a basis for efficient field application.
Assuntos
Hemípteros/genética , Controle de Insetos/métodos , Mariposas/genética , Interferência de RNA , Gorgulhos/genética , Animais , América Central , Genes Letais , América do Sul , Clima TropicalRESUMO
STUDY OBJECTIVES: In this study we evaluated the role of three currently available therapeutic regimens in the treatment of early stages of idiopathic pulmonary fibrosis (IPF). PATIENTS: The study population consisted of 57 consecutive suspected individuals with IPF. Patients with interstitial pneumonias other than IPF and subjects with advanced disease or contraindication to therapy were excluded. We evaluated 30 subjects with mild-moderate IPF, homogeneous baseline characteristics and prognostic parameters that were assigned to 3 treatment regimens: group 1 (n = 11): prednisone 1 mg/kg/ day; group 2 (n = 9): prednisone 0.5 mg/kg/day plus cyclophosphamide 100 mg/day; group 3 (n = 10): prednisone 0.5 mg/kg/day plus colchicine 1 mg/day. We analysed response to therapy by analysis of a clinical-radiographic-physiologic (CRP) score before treatment and at 6 months intervals for 18 months. Side effects and three years survival rate were also investigated. RESULTS: Although our study was performed in a subset of patients with early disease's stages, these data showed that none of the regimens was able to interfere with IPF's course. However treatment with colchicine plus prednisone resulted in fewer side effects and re-evaluation parameters showed a significant decrease of dyspnoea (p < 0.01). No significant differences were observed in survival rate among the three groups. CONCLUSIONS: None of the regimens analyzed was effective even in the treatment of the early stages of IPF. The association colchicine/corticosteroids could be considered a safe and not expensive regimen that may be used in the treatment of IPF, especially in patients who have experienced adverse effects from immunosuppressive agents, while waiting for newer therapeutic strategies.
Assuntos
Colchicina/uso terapêutico , Ciclofosfamida/uso terapêutico , Prednisona/uso terapêutico , Fibrose Pulmonar/tratamento farmacológico , Idoso , Colchicina/efeitos adversos , Ciclofosfamida/efeitos adversos , Quimioterapia Combinada , Dispneia/tratamento farmacológico , Dispneia/etiologia , Feminino , Seguimentos , Glucocorticoides/administração & dosagem , Glucocorticoides/efeitos adversos , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Prednisona/efeitos adversos , Testes de Função Respiratória , Taxa de Sobrevida , Moduladores de Tubulina/efeitos adversos , Moduladores de Tubulina/uso terapêuticoRESUMO
Aspergillus sydowii is a cosmopolitan fungus that has been responsible for the mass destruction of coral in the Caribbean Sea over the last 15years. To our knowledge, this study has found the first case of A. sydowii in the Mediterranean Sea, in marine-bottom sediments, water and calcareous shells of bivalve molluscs sampled during a campaign to characterise the mycobiota in the Port of Genoa (Italy). The area is characterised by adverse environmental conditions (high turbidity, organic pollution and high concentrations of phosphorus and nitrogen compounds). These parameters, in combination with a rising temperature, could contribute to A. sydowii bloom and dispersal. This fungal strain may have been imported into the Port of Genoa in the bilge water of vessels or by torrent input. This work represents the first step in the implementation of a monitoring programme to safeguard calcareous sponges and sea fan corals endemic in the Mediterranean Sea.
Assuntos
Aspergillus , Monitoramento Ambiental , Animais , Antozoários , Aspergillus/patogenicidade , Região do Caribe , Recifes de Corais , Itália , Mar Mediterrâneo , Microbiologia da ÁguaRESUMO
Fungi include a vast group of eukaryotic organisms able to colonise different natural, anthropised and extreme environments, including marine areas contaminated by metals. The present study aims to give a first multidisciplinary characterisation of marine bottom sediments contaminated by metals (Cd, Co, Cr, Cu, Ni, and Zn), originating in the water leakage from an abandoned Fe-Cu sulphide mine (Libiola, north-western Italy), and evaluate how the chemical and physical parameters of water and sediments may affect the benthic fungal communities. Our preliminary results showed the high mycodiversity of the marine sediments studied (13 genera and 23 species of marine fungi isolated), and the great physiological adaptability that this mycobiota evolved in reaction to the effects of the ecotoxic bottom sediment contamination, and associated changes in the seawater parameters.
Assuntos
Fungos , Metais Pesados/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Sedimentos Geológicos , Itália , Metais Pesados/toxicidade , Valores de Referência , Água do Mar , Microbiologia da Água , Poluentes Químicos da Água/toxicidadeRESUMO
BACKGROUND: Although the feasibility of minimally invasive resection of small gastric GISTs is well established, less is known about safety and efficacy of laparoscopic surgery for large tumors. METHODS: A retrospective analysis was performed, using a prospectively maintained comprehensive database. Patients were divided into two groups according to tumor size: Case group with tumors > 5 cm and control group with tumors <5 cm. Hospital charts were reviewed, and various outcome measures recorded, including operative time, estimated operative blood loss, post-operative leak, stasis, infection and recurrence. RESULTS: No tumors were ruptured during surgical manipulation and no major morbidity or mortality occurred in either group. Operative time (75,8 ± 33,1 min in large cases vs 75,8 ± 33,1 min in small cases) was similar in both groups (p = 0,61). The incidence of post-operative complications did not differ between the two groups. In details there were 21 out of 25 (84%) uncomplicated cases among small GISTs versus 17 out of 24 (70,8%) uncomplicated cases among large GISTs (p = 0,32). CONCLUSION: This matched-pair case control study demonstrates that laparoscopic wedge resection for large gastric GISTs is safe and effective, as demonstrated for small tumors.
Assuntos
Gastrectomia/métodos , Tumores do Estroma Gastrointestinal/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Neoplasias Gástricas/cirurgia , Idoso , Idoso de 80 Anos ou mais , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Estudos de Casos e Controles , Bases de Dados Factuais , Feminino , Tumores do Estroma Gastrointestinal/patologia , Humanos , Incidência , Infecções/epidemiologia , Laparoscopia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos Retrospectivos , Neoplasias Gástricas/patologia , Carga TumoralRESUMO
Structural integrity of the hepatitus C virus (HCV) 5' UTR region that includes the internal ribosome entry site (IRES) element is known to be essential for efficient protein synthesis. The functional explanation for this observation has been provided by the recent evidence that binding of several cellular factors to the HCV IRES is dependent on the conservation of its secondary structure. In order to better define the relationship between IRES activity, protein binding and RNA folding of the HCV IRES, we have focused our attention on its major stem-loop region (domain III) and the binding of several cellular factors: two subunits of eukaryotic initiation factor eIF3 and ribosomal protein S9. Our results show that binding of eIF3 p170 and p116/p110 subunits is dependent on the ability of the domain III apical stem-loop region to fold in the correct secondary structure whilst secondary structure of hairpin IIId is important for the binding of S9 ribosomal protein. In addition, we show that binding of S9 ribosomal protein also depends on the disposition of domain III on the HCV 5' UTR, indicating the presence of necessary inter-domain interactions required for the binding of this protein (thus providing the first direct evidence that tertiary folding of the HCV RNA does affect protein binding).
Assuntos
Hepacivirus/genética , Conformação de Ácido Nucleico , RNA Viral/química , Animais , Sequência de Bases , Células COS , Primers do DNA , Dados de Sequência MolecularRESUMO
The time has passed for us to wonder whether RNA interference (RNAi) effectively controls pest insects or protects beneficial insects from diseases. The RNAi era in insect science began with studies of gene function and genetics that paved the way for the development of novel and highly specific approaches for the management of pest insects and, more recently, for the treatment and prevention of diseases in beneficial insects. The slight differences in components of RNAi pathways are sufficient to provide a high degree of variation in responsiveness among insects. The current framework to assess the negative effects of genetically modified (GM) plants on human health is adequate for RNAi-based GM plants. Because of the mode of action of RNAi and the lack of genomic data for most exposed non-target organisms, it becomes difficult to determine the environmental risks posed by RNAi-based technologies and the benefits provided for the protection of crops. A better understanding of the mechanisms that determine the variability in the sensitivity of insects would accelerate the worldwide release of commercial RNAi-based approaches.
Assuntos
Controle de Insetos/métodos , Insetos/genética , Controle Biológico de Vetores/métodos , Interferência de RNA , Doenças dos Animais/prevenção & controle , Animais , Meio Ambiente , MicroRNAs/fisiologia , RNA Interferente Pequeno/fisiologia , Medição de Risco , VirosesRESUMO
In this paper the discussion focuses on a decision support system to be used as a tool in the treatment of poisoning cases attributable to mushrooms, plants and animals. In this first release, attention is focused on the risks related to fungi. Problems involved with mushroom poisoning and identification are analyzed to highlight which elements or characters must be taken into account in devising a computerized expert system. The components of such a system are presented, the different approaches are discussed and the choices made are motivated. Some preliminary results are also presented.
Assuntos
Sistemas de Apoio a Decisões Clínicas , Intoxicação Alimentar por Cogumelos/terapia , Intoxicação por Plantas/terapia , Inteligência Artificial , Bases de Dados Factuais , Humanos , Modelos TeóricosRESUMO
The dissemination of research through publication in professional journals is important for the advancement of pediatric nursing practice. Without knowledge of current research, practitioners cannot take actions to apply research to improve the health of the children and families they serve. To ensure that practitioners can make the most appropriate use of quantitative research findings, research publications must adhere to specific scientific standards for the conduct and reporting of research. This article is intended to guide nurse researchers to adhere to these standards and effectively communicate their research findings to nurses in clinical practice.
Assuntos
Pesquisa em Enfermagem Clínica , Difusão de Inovações , Publicações Periódicas como Assunto , Redação , Humanos , Enfermagem PediátricaRESUMO
In recent years, a great deal of research has been devoted to identify new natural sources of phytosterols and to improve methods for their recovery and purification. In this regard, unexplored natural sources of bioactive ingredients are gaining much attention since they can lead to the isolation of new compounds or bioactivities. The field of available natural sources has been further increased by including algae and, even more interestingly, microalgae. In the present study, a multidisciplinary approach has been used considering, in an integrated view, extraction, chemical composition and bioactivity of phytosterols from the microalga Dunaliella tertiolecta. A novel methodology to extract, separate and characterize microalgal-derived phytosterols has been developed. In addition, recoverable and reusable eluents have been selected in order to reduce the quantities of employed organic solvents. Finally, we addressed the question whether orally administered phytosterols reach the brain and if those interfere with the major neurotransmitter systems, such as the dopaminergic, serotoninergic and noradrenergic ones, in several brain areas of rats. Flash Liquid Chromatography has been used to separate the Total Sterol (TS) fraction, composed of twelve sterols, with a purity of 97.87% and a recovery percentage of 98%, while the "flash version" of Silver Ion Liquid Chromatography has been used to purify the most abundant phytosterols in TS, (22E,24R)- methylcholesta-5,7,22-trien-3ß-ol (ergosterol) and (22E,24R)-ethylcholesta-5,7,22-trien-3ß-ol (7-dehydroporiferasterol), with a purity of 97.4%. These two combined methods did not need sophisticated technologies but only cheap laboratory supplies. Moreover, the possibility of recovering and recycling the solvents used as eluents made it a cleaner process. Finally, for the first time, a neuromodulatory action of Dunaliella tertiolecta-derived phytosterols has been found in selective brain areas of rats.
Assuntos
Encéfalo/efeitos dos fármacos , Clorófitas/química , Fitosteróis/isolamento & purificação , Fitosteróis/farmacologia , Animais , Encéfalo/metabolismo , Dopamina/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Norepinefrina/metabolismo , Fitosteróis/química , Ratos , Ratos Wistar , Serotonina/metabolismo , Espectrometria de Massas em TandemRESUMO
BACKGROUND AND PURPOSE: There is growing evidence that inflammation plays a major role in the pathogenesis of neural damage caused by deposition of amyloid ß (Aß) in the brain. Nimodipine has received attention as a drug that might improve learning and reduce cognitive deficits in Alzheimer's disease, but the mechanism of action is poorly known. In this study, we tested the hypothesis that nimodipine inhibited Aß-stimulated IL-1ß release from microglia. EXPERIMENTAL APPROACH: Cultures of N13 microglia cells or primary mouse microglia were treated with nimodipine, and intracellular accumulation and release of IL-1ß in response to Aß or to the P2 receptor agonists ATP and benzoyl ATP (BzATP) were measured. Accumulation of IL-1ß was measured in vivo after intrahippocampal inoculation of Aß in the absence or presence of nimodipine. The effect of nimodipine on Aß-triggered cytotoxicity was also investigated. KEY RESULTS: We show here that nimodipine dose-dependently inhibited Aß-stimulated IL-1ß synthesis and release from primary microglia and microglia cell lines. Furthermore, nimodipine also inhibited Aß-induced IL-1ßin vivo accumulation at concentrations known to be reached in the CNS. Finally, nimodipine protected microglia from Aß-dependent cytotoxicity. CONCLUSION AND IMPLICATIONS: These data suggest that alleviation of symptoms of Alzheimer's disease following nimodipine administration might be due to an anti-inflammatory effect and point to a novel role for nimodipine as a centrally acting anti-inflammatory drug.
Assuntos
Anti-Inflamatórios/farmacologia , Interleucina-1beta/antagonistas & inibidores , Microglia/efeitos dos fármacos , Nimodipina/farmacologia , Doença de Alzheimer , Peptídeos beta-Amiloides , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Camundongos , Microglia/metabolismoRESUMO
BACKGROUND: Galanin participates in the pathogenesis of acute pancreatitis (AP). The galanin receptor (GALR) sub-types involved, however, are unclear. We aimed to determine GALRs messenger RNA (mRNA) expression in mouse pancreas, describe their localization, and ascertain if GALR2 and GALR3 are involved in AP. METHODS: Galanin receptor expression in murine whole pancreas, acinar, and islet cells was quantified by polymerase chain reaction amplification of reverse-transcribed RNA for mRNA, Western blot analysis for protein and in situ hybridization for GALR localization. Isolated acinar cells were used to determine galanin's effect on amylase secretion. Acute pancreatitis was induced in mice by caerulein injections. Mice, with and without AP, were treated with the highly selective GALR2 antagonist M871, or the specific GALR3 antagonist SNAP-37889. Indices of AP were measured at 12 h. KEY RESULTS: Murine pancreas expresses mRNA for GALRs. In islets the expression of all GALR are comparable, whereas in acinar cells GALR3 is predominantly expressed. Western blot analysis confirmed that the GALR proteins are expressed by acinar cells. In situ hybridization analysis confirmed that GALR3 mRNA is present in islet and acinar cells, while mRNA for GALR1 and 2 is confined to islets. Galanin did not influence basal and caerulein-stimulated amylase release from acinar cells. M871 treatment reduced some, whereas SNAP-37889 treatment reduced all indices of AP (by 40-80%). CONCLUSIONS & INFERENCES: Galanin receptor mRNA and protein are expressed in mouse pancreas, with GALR3 mRNA predominating. GALR3 antagonism reduced the severity of AP whereas GALR2 antagonism was less effective. GALR3 is a potential target for treatment of AP.
Assuntos
Galanina/metabolismo , Pancreatite/tratamento farmacológico , Receptor Tipo 3 de Galanina/metabolismo , Doença Aguda , Amilases/metabolismo , Animais , Células Cultivadas , Humanos , Indóis/farmacologia , Camundongos , Pâncreas/citologia , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Pancreatite/fisiopatologia , Peroxidase/metabolismo , RNA Mensageiro/metabolismo , Distribuição Aleatória , Receptor Tipo 3 de Galanina/antagonistas & inibidores , Receptor Tipo 3 de Galanina/genéticaRESUMO
BACKGROUND AND PURPOSE: Depression is common in early phases of Alzheimer's disease (AD) and may represent prodromal symptoms of dementia. Recent reports suggest that early memory deficits and neuropsychiatric symptoms are caused by soluble rather than aggregated betaamyloid (Abeta). Thus, we investigated the effects of soluble Abeta(1-42) on working memory and depressive/anxiety-related behaviour in rats and on 5-hydroxytryptaminergic neurotransmission and neurotrophin content in various brain regions. EXPERIMENTAL APPROACH: Behavioural reactivity to novel object recognition, open field, elevated plus maze and forced swimming test were assessed 7 days after i.c.v. injection of Abeta(1-42) or its vehicle. BDNF (brain-derived neurotrophic factor) and NGF (nerve growth factor) mRNA and protein levels and 5-hydroxytriptamine (5-HT) content were measured in the prefrontal cortex (PFC), striatum (STR) and nucleus accumbens (NAc). KEY RESULTS: Abeta(1-42) did not affect the ability to distinguish between familiar and novel objects, but Abeta-treated rats exhibited an increase in forced swimming immobility. No differences were revealed between experimental groups in the elevated plus maze test or in self-grooming (evaluated in the open field). In the PFC, but not STR or NAc, Abeta-injected rats exhibited a selective reduction in 5-HT content, BDNF and NGF expression. CONCLUSIONS AND IMPLICATIONS: Our data suggest that soluble Abeta-treated rats have a depressive, but not anxiogenic-like, profile, accompanied by brain region-dependent alterations in the expression of neurotrophins and 5-hydroxytryptaminergic neurotransmission. Hence, these alterations induced by soluble Abeta might be sensitive indicators of early phases of AD and possible risk factors for the expression of neuropsychiatric symptoms in AD.
Assuntos
Peptídeos beta-Amiloides/farmacologia , Comportamento Animal/efeitos dos fármacos , Depressão/induzido quimicamente , Fragmentos de Peptídeos/farmacologia , Peptídeos beta-Amiloides/administração & dosagem , Animais , Sequência de Bases , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Primers do DNA , Injeções Intraventriculares , Masculino , Aprendizagem em Labirinto , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Fragmentos de Peptídeos/administração & dosagem , Ratos , Ratos Wistar , Serotonina/metabolismoRESUMO
O objetivo do trabalho foi avaliar a seletividade de inseticidas usados na cultura do milho para o controle de Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) sobre ninfas de primeiro ínstar e ovos do predador Doru lineare (Scudder, 1876) (Dermaptera: Forficulidae). Para os bioensaios foi utilizada a metodologia padronizada da IOBC/WPRS, em condições de laboratório, com temperatura de 25 ± 1º C, umidade relativa de 70 ± 10% e fotofase de 14 horas. No bioensaio com ninfas para contato residual, a aplicação dos inseticidas foi realizada com um equipamento pressurizado a CO2, pressão de 50 psi. Para aplicação dos inseticidas sobre os ovos foi utilizada torre de Potter, com pressão de 10 psi. Em ambas as formas de aplicação o depósito foi de 1,75 ± 0,25 mg de calda cm-2 conforme metodologia da IOBC/WPRS. A mortalidade de ninfas foi utilizada para classificar os inseticidas como inócuo (< 30%), levemente nocivo (30-79%), moderadamente nocivo (80-99%) e nocivo (> 99%). Os dados de viabilidade de ovos e sobrevivência de ninfas que eclodiram deles foram comparados com os dados das testemunhas positiva (Sevin 480 SC) e negativa (água). Certero, Dimilin, Engeo Pleno, Karate Zeon 250 SC, Lorsban 480 BR, Match EC e Sevin 480 SC reduziram a viabilidade de ovos. A sobrevivência de ninfas provenientes dos ovos tratados teve redução para os inseticidas: Decis 25 EC, Dimilin, Engeo Pleno, Karate Zeon 250 CS, Lorsban 480 BR e Sevin 480 SC. Para ninfas de D. lineare em contato residual, todos os inseticidas foram nocivos em 96 horas após a exposição.
The goal of this work was to evaluate the selectivity of insecticides used in corn crops for the control of Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) on first-instar nymphs and eggs of the earwig Doru lineare. For the bioassays the standardized methodology of IOBC/WPRS was used in terms of temperature (25 ± 1º C), relative humidity (70 ± 15%) and photophase (14 hours). In the bioassay with nymphs for residual contact, the applications of insecticides was conducted with equipment pressurized by CO2 to 50 psi. For applications of insecticides on eggs, a Potter's tower was used, with pressure of 10 psi. In both forms of spraying the deposit was 1.75±0.25 mg cm-2 of aqueous solution in accordance with the IOBC/WPRS methodology. The mortality of nymphs was used to classify insecticides as harmless (< 30%), slightly harmful (30-79%), moderately harmful (80-99%) and harmful (> 99%). Viability of eggs and survival of hatched nymphs were both evaluated by comparing with the positive (Sevin 480 SC) and negative (water) controls. The viability of eggs was reduced by Certero, Dimilin, Engeo Pleno, Karate Zeon 250 SC, Lorsban 480 BR, Match EC and Sevin 480 SC. The survival of nymphs from treated eggs was reduced by the insecticides Decis EC, Dimilin, Engeo Pleno, Karate Zeon 250 CS, Lorsban 480 BR and Sevin 480 SC. For nymphs of D. lineare in residual contact, all the insecticides were harmful.
Assuntos
Controle de Insetos/métodos , Zea mays/parasitologia , Inseticidas/administração & dosagem , Insetos/parasitologiaRESUMO
O objetivo do presente trabalho foi avaliar a seletividade dos inseticidas utilizados na cultura do milho sobre Doru lineare. Foi avaliada a seletividade de inseticidas utilizados na cultura do milho para D. lineare, seguindo metodologia proposta pela IOBC/WPRS em condições de laboratório. Adultos foram expostos aos resíduos dos inseticidas por meio de contato com placas de vidros e pelo consumo de ovos de Spodoptera frugiperda contaminados com os inseticidas. A porcentagem de mortalidade dos insetos em contato residual foi utilizada para classificar os inseticidas como inócuo (< 30%), levemente nocivo (30-79%), moderadamente nocivo (80-99%) e nocivo (> 99%). A mortalidade de adultos após consumo de ovos contaminados foi comparada com a testemunha. Para adultos deD. lineare mediante contato residual, nas 360 HAIE (horas após o início da exposição), os inseticidas Decis 25 EC, Dimilin, Engeo Pleno, Karate Zeon 250 CS, Lorsban 480 BR, Match EC, Neem Azal e Sevin 480 SC foram nocivos ao predador. Certero, Fastac 100 SC e Tracer foram moderadamente nocivos. Intrepid 240 SC e Mimic 240 SC foram inócuos. A mortalidade de adultos após o consumo de ovos contaminados foi significativa para os inseticidas Certero, Dimilin, Tracer, Engeo Pleno, Lorsban 480 BR, Sevin 480 SC.
The objective of this work was to evaluate the selectivity of insecticides used in the corn crop to Doru lineare (Eschscholtz, 1822) (Dermaptera: Forficulidae), following methodology suggested by IOBC/WPRS, under laboratory conditions. Adult insects were placed on glass plates or fed on Spodoptera frugiperda eggs, both containing previously sprayed insecticide residues. The adult mortality by the residual contact was used to classify insecticides as harmless (< 30%), slightly harmful (30-79%), moderately harmful (80-99%) and harmful (> 99%). The adult mortality due to consumption of the contaminated eggs was compared to the control. For adults ofD. linearein residual contact after 360 HASE (hours after start of exposure) the insecticides Decis 25 EC, Dimilin, Engeo Pleno, Karate Zeon 250 CS, Lorsban 480 BR, Match EC, Neem Azal and Sevin 480 SC were harmful. Certero, Fastac 100 SC and Tracer were moderately harmful. Intrepid 240 SC and Mimic 240 SC were slightly harmful. The mortality of adults after consumption of contaminated eggs was noteworthy for the insecticides Certero, Dimilin, Tracer, Engeo Pleno, Lorsban 480 BR and Sevin 480 SC.