ABSTRACT
This study aimed to explore attentional patterns among children with inattentive attention-deficit/hyperactivity disorder (ADHD-I) and children with typical development (TD), using a latent class analysis (LCA). Patterns of brain connectivity were also explored. The sample comprised 29 ADHD-I and 29 TD matched children. An LCA was conducted to reclassify subjects according to their attentional performance, considering cognitive measures of attention and behavioral symptoms, regardless of group of origin. The new clusters were then compared in respect to brain white matter measurements (extracted from diffusion tensor imaging). Participants were rearranged in 2 new latent classes, according to their performance in an attention task and the results of behavioral scales, resulting in groups with more homogeneous attentional profiles. A comparison of the 2 new classes using the white matter measurements revealed increased fractional anisotropy in the left inferior fronto-occipital fasciculus and left inferior longitudinal fasciculus for the class composed by participants with a higher risk of attentional problems. The findings indicated that it was possible to observe variability regarding neuropsychological profile, accompanied by underpinning neurobiological differences, even among individuals with the same disorder subtype - inattentive ADHD. This specific data-driven clustering analysis may help to enhance understanding of the pathophysiology of the disorder's phenotypes.
Subject(s)
Humans , Male , Female , Child , Adolescent , Attention/physiology , Attention Deficit Disorder with Hyperactivity/physiopathology , White Matter/physiopathology , Reaction Time/physiology , Reference Standards , Reference Values , Attention Deficit Disorder with Hyperactivity/diagnosis , Case-Control Studies , Statistics as Topic/methods , Anisotropy , Cognition/physiology , Diffusion Tensor Imaging/methods , White Matter/diagnostic imaging , Neuropsychological TestsABSTRACT
Studies were carried out to evaluate the efficacy of the growth regulator, triflumuron (TFM) (Starycide® sc 480 Bayer), for disrupting the development of Rhodnius prolixus fifth-instar nymph by oral, topical or continuous treatment. All treatments were able to induce high levels of mortality, delay development and molt inhibition. Oral treatment induced molt inhibition in all insects that survived at doses of 0.25, 0.50 and 5.0 mg/mL of a blood meal. The highest levels of both mortality in 24 h and molt inhibition were always observed after topical treatment. The lowest doses needed to obtain considerable biological effects were always observed after continuous treatment. In this way, the highest levels of mortality within 30 days were detected after continuous treatment, which also induced an extended inter-molting period, a lower number of over-aged nymphs and the highest level of molting in nymphs that survived. Moreover, the effects of TFM on insects were often displayed in a dose response manner. These results indicate that TFM acts as a potent growth inhibitor of R. prolixus nymphs and has the potential to be used in integrated vector control programs against hematophagous triatomine species.
Subject(s)
Animals , Male , Benzamides/pharmacology , Insecticides/pharmacology , Rhodnius/drug effects , Dose-Response Relationship, Drug , Nymph/drug effects , Nymph/growth & development , Rhodnius/growth & development , Time FactorsABSTRACT
The effects of blood components, nerve-cord severance, and ecdysone therapy on the posterior midgut epithelial cells of 5th-instar Rhodnius prolixus nymphs 10 days after feeding were analyzed by transmission electron microscopy. Cutting the nerve-cord of the blood-fed insects partially reduced the development of microvilli and perimicrovillar membranes (PMM), and produced large vacuoles and small electrondense granules; insects fed on Ringer's saline diet exhibited well developed microvilli and low PMM production; swolled rough endoplasmatic reticulum and electrondense granules; Ringer's saline meal with ecdysone led to PMM development, glycogen particles, and several mitochondria in the cytoplasm; epithelial cells of the insects fed on Ringer's saline meal whose nerve-cord was severed showed heterogeneously distributed microvilli with reduced PMM production and a great quantity of mitochondria and glycogen in the cytoplasm; well developed microvilli and PMM were observed in nerve-cord severed insects fed on Ringer's saline meal with ecdysone; Ringer's saline diet containing hemoglobin recovered the release of PMM; and insects fed on human plasma showed slightly reduced PMM production, although the addition of ecdysone in the plasma led to a normal midgut ultrastructural organization. We suggest that the full development of microvilli and PMM in the epithelial cells depends on the abdominal distension in addition to ingestion of hemoglobin, and the release of ecdysone.
Subject(s)
Animals , Male , Blood , Ecdysone , Microvilli , Rhodnius , Intestines , Microscopy, Electron , NymphABSTRACT
Ácido oleanólico apresenta no barbeiro Rhodnius prolixus, vetor da doença de Chagas, toxicidade dosedependente e drástica inibição da muda nas doses de 1, 10 e 100 mg/ml. Eugenol induz uma letargia que persiste por vários dias, apresenta forte fagorrepelência, toxicidade média e inibição total da muda nas doses de 10 e 100 mg/ml.
ABSTRACT
Säo apresentados os resultados de marcaçäo, soltura e recaptura de pacus (Piaractus mesopotamicus Holmberg, 1887) oriundos de desova induzida em laboratório. Os peixes foram criados nos sistemas de tanques-rede e tanque de terra, alimentados com raçäo peletizada e soltos em dois lotes (16 e 33 meses de idade) no reservatório da UHE Itutinga (CEMIG) - Rio Grande. Utilizaram-se marcas do tipo hidrostática com mensagem interna, costuradas entre as nadadeiras dorsal e adiposa. Dos 1866 peixes soltos, resgataram-se 62 marcas com os dados de captura, sendo 71 por cento recuperadas a jusante da UHE Itutinga. Constatou-se a passagem de peixes através das turbinas verticais tipo Kaplan ou tipo Hélice e registrou-se a distância de até 185km percorrida por alguns exemplares a jusante da UHE Itutinga. Os peixes capturados apresentaram crescimento em peso e comprimento, demonstrando assim, capacidade de adaptaçäo ao novo ambiente
Subject(s)
Animals , Behavior, Animal , Fishes/growth & developmentABSTRACT
Säo apresentados os resultados de pesca e induçäo da reproduçäo de peixes coletados a jusante da UHE Itutinga (CEMIG), no Rio Grande. Foi realizada avaliaçäo da condiçäo reprodutiva dos peixes que alcançavam aquela parte do Rio, baseada na identificaçäo macroscópica do sexo e estádio de maturaçäo gonadal (EMG) e do cálculo do índice gonadossomático (IGS). Exemplares de curimbatá (Prochilodus scrofa), piapara (Leporinus elongatus) e piau (Leporinus friderici) foram submetidos à reproduçäo induzida. Tanto piaparas quanto piaus responderam positivamente à induçäo da reproduçäo. Ficou comprovada a viabilidade técnica e econômica desta técnica de manejo para a propagaçäo de espécies de peixes impossibilitadas de migrarem rio acima
Subject(s)
Animals , Fishes/anatomy & histology , Gonads/anatomy & histology , ReproductionABSTRACT
No reservatório da Usina Hidrelétrica de Itutinga, da Companhia Energética de Minas Gerais (CEMIG), realizou-se um experimento no período de outubro de 1992 a abril de 1993. Estudaram-se os efeitos da frequência de alimentaçäo (1, 3 e 5 vezes/dia) e densidade de estocagem (40 e 80 peixes/m cúbico) sobre o desempenho produtivo do Piararactus mesopotamicus, com peso médio inicial de 23,8 mais ou menos 0,77g e comprimento médio total de 10,5 mais ou menos 0,17 cm. Os resultados de ganho de peso total e diário (g), taxa de crescimento relativo e específico (porcentagem), crescimento médio (cm) foram maiores nas frequências de 3 e 5 vezes ao dia (P<0,05) independente da densidade de estocagem. A estocagem de 80 peixes/m cúbico e arraçoamento parcelado em 3 vezes ao dia proporcionam melhores resultados de crescimento de pacus estocados em tanques-rede
Subject(s)
Animals , Animal Feed , FishesABSTRACT
Trypanosoma cruzi strain Y and clone Dm28c and other trypanosomatids were exposed to two lytic agents, Rhodnius prolixus hemolytic factor (RHF) and mellitin, in vitro. In both cases, the result was a significant decrease in the number of parasites after a 30-min treatment at 37-C. RHF and mellitin had distinct activities on differente strains and species of trypanosomatids. These observations suggest that RHF may be an important factor in selecting resistant strains of trypanosomes for development in the vector's gut