177 research outputs found

    Impulsivity and the 5-HTTLPR Polymorphism in a Non-Clinical Sample

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    BACKGROUND: Impulsivity has been associated with serotonergic system functions. However, few researchers have investigated the relationship between a polymorphism in the promoter of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population. The aim of this study was to investigate the relationship between a polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population. METHODOLOGY/PRINCIPAL FINDINGS: We administered two neuropsychological tests, the Continuous Performance Task and the Iowa Gambling Task, to 127 healthy participants to measure their levels of motor, attentional and non-planning impulsivity. Then, these participants were grouped by genotype and gender, and their scores on impulsivity measures were compared. There were no significant differences between group scores on attentional, motor and non-planning impulsivity. CONCLUSIONS/SIGNIFICANCE: Our results suggest that 5-HTTLPR genotype is not significantly associated with subsets of impulsive behavior in a non-clinical sample when measured by neuropsychological tests. These findings are discussed in terms of the sensitivity of neuropsychological tests to detect impulsivity in a non-clinical population and the role of gender and race in the relationship between the 5-HTTLPR and impulsivity

    Drug discovery for Chagas disease should consider Trypanosoma cruzi strain diversity.

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    This opinion piece presents an approach to standardisation of an important aspect of Chagas disease drug discovery and development: selecting Trypanosoma cruzi strains for in vitro screening. We discuss the rationale for strain selection representing T. cruzi diversity and provide recommendations on the preferred parasite stage for drug discovery, T. cruzi discrete typing units to include in the panel of strains and the number of strains/clones for primary screens and lead compounds. We also consider experimental approaches for in vitro drug assays. The Figure illustrates the current Chagas disease drug-discovery and development landscape

    SAND FLY SPECIES COMPOSITION (DIPTERA: PSYCHODIDAE: PHLEBOTOMINAE) IN THE MUNICIPALITY OF CANTAGALO , AN AREA WITH SPORADIC CASES OF HUMAN CUTANEOUS LEISHMANIASIS IN RIO DE JANEIRO STATE, BRAZIL

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    SUMMARY The municipality of Cantagalo is an area with sustained transmission of American Cutaneous Leishmaniasis (ACL). Monthly sand fly collections were performed for three years (June 2012 - May 2015) using a CDC light trap. A total of 3,310 specimens belonging to 12 species were trapped: Nyssomyia intermedia, Nyssomyia whitmani, Migonemyia migonei, Evandromyia lenti, Evandromyia cortelezzii, Micropygomyia quinquefer, Brumptomyia brumpti, Psathyromyia aragaoi, Micropygomyia schreiberi, Pintomyia fischeri, Sciopemyia sordellii, and Evandromyia edwardsi. The last seven species have not been previously recorded in this area. The highest abundance of species occurred between October and March. October was the month with the highest number of captured sand flies, one month before the peak in the summer rainfall. In October the highest number of Ny. intermedia, Ny. whitmani and Mg. migonei, were also collected, the three epidemiologically most important species. The high abundance of species with epidemiological importance for ACL transmission might explain the sporadic occurrence of the disease in the area

    Cross-species chromosome painting tracks the independent origin of multiple sex chromosomes in two cofamiliar Erythrinidae fishes

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    <p>Abstract</p> <p>Background</p> <p>The Erythrinidae fish family is characterized by a large variation with respect to diploid chromosome numbers and sex-determining systems among its species, including two multiple X<sub>1</sub>X<sub>2</sub>Y sex systems in <it>Hoplias malabaricus </it>and <it>Erythrinus erythrinus</it>. At first, the occurrence of a same sex chromosome system within a family suggests that the sex chromosomes are correlated and originated from ancestral XY chromosomes that were either homomorphic or at an early stage of differentiation. To identify the origin and evolution of these X<sub>1</sub>X<sub>2</sub>Y sex chromosomes, we performed reciprocal cross-species FISH experiments with two sex-chromosome-specific probes designed from microdissected X<sub>1 </sub>and Y chromosomes of <it>H. malabaricus </it>and <it>E. erythrinus</it>, respectively.</p> <p>Results</p> <p>Our results yield valuable information regarding the origin and evolution of these sex chromosome systems. Our data indicate that these sex chromosomes evolved independently in these two closed related Erythrinidae species. Different autosomes were first converted into a poorly differentiated XY sex pair in each species, and additional chromosomal rearrangements produced both X<sub>1</sub>X<sub>2</sub>Y sex systems that are currently present.</p> <p>Conclusions</p> <p>Our data provide new insights into the origin and evolution of sex chromosomes, which increases our knowledge about fish sex chromosome evolution.</p
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