RESUMO
The aim of this study was to determine the selection of bedding material by broiler chickens during the rearing period and whether the choice was determinant to their performing a specific behavior. To achieve this objective, a choice test was designed. A choice pen was constructed where birds could move freely around the four selected materials (straw, wood shavings, rice hulls and sand). Chickens were introduced in this pen in four groups of eight birds, three days a week for one hour per day and group, for four weeks. The location and the activity performed by each broiler were recorded every five minutes. Results showed a preference for sand compared with the other three substrates. However, differences between the behaviors performed in each bedding material were shown mainly for resting (preferably performed on wood shavings and straw), dust bathing (on sand), pecking and scratching (on rice hulls). Other factors, such as the time of day, were also found to have effects on fighting and drinking, and changes in behavioral patterns (resting, preening, eating, standing and pecking) were also detected as broilers grew older.(AU)
Assuntos
Animais , Aves Domésticas/classificação , Aves Domésticas/crescimento & desenvolvimento , Comportamento Animal , Substratos para Tratamento BiológicoRESUMO
We present a comprehensive study of semiclassical phase-space propagation in the Wigner representation, emphasizing numerical applications, in particular as an initial-value representation. Two semiclassical approximation schemes are discussed. The propagator of the Wigner function based on van Vleck's approximation replaces the Liouville propagator by a quantum spot with an oscillatory pattern reflecting the interference between pairs of classical trajectories. Employing phase-space path integration instead, caustics in the quantum spot are resolved in terms of Airy functions. We apply both to two benchmark models of nonlinear molecular potentials, the Morse oscillator and the quartic double well, to test them in standard tasks such as computing autocorrelation functions and propagating coherent states. The performance of semiclassical Wigner propagation is very good even in the presence of marked quantum effects, e.g., in coherent tunneling and in propagating Schrodinger cat states, and of classical chaos in four-dimensional phase space. We suggest options for an effective numerical implementation of our method and for integrating it in Monte-Carlo-Metropolis algorithms suitable for high-dimensional systems.
RESUMO
The combination of artesunate and mefloquine is one of the most effective treatments against multidrug-resistant falciparum malaria. Experience in children is however limited. The objective of this study was to compare the efficacy and safety of two artesunate/mefloquine combinations with artesunate monotherapy in Ecuadorian children. A total of 150 children with an age between 2 and 12 years, confirmed to have uncomplicated falciparum malaria, were randomly selected and divided in three treatment groups of 50 patients each. Group 1 received 50 mg rectal capsules alone (40 mg/kg total dose) administered over 6 days. Group 2 received 50 mg rectal capsules (30 mg/kg total dose) for 3 days combined with mefloquine (20 mg/kg total dose) on day 1. Group 3 was treated with 50 mg rectal capsules (30 mg/kg total dose) for 3 days, combined with mefloquine on days 1 and 3 (15-17 mg/kg total dose). Patients were continuously followed up and controlled by clinical and laboratory examinations for 7 days as well as on days 14, 21 and 28. An additional parasite examination was performed at 2 months following therapy. Clearance of parasitaemia was comparable between treatment groups. These were 9.2, 9.2 and 8.3 h for Groups 1, 2 and 3, respectively. Cure rates at day 28 were 76, 96 and 94% and after 2 months 60, 88 and 80%, respectively. There were no adverse events (AEs) reported during the study. Vital signs and laboratory examinations revealed no changes of clinical relevance. It can be concluded that the combination of artesunate rectal capsules with mefloquine is effective and safe. Starting concomitant administration already on day 1 is well tolerated. This combination significantly reduces the incidence of recrudescence compared to artesunate monotherapy. Comparing the two tested artesunate/mefloquine regimens, a total mefloquine dose of 20 mg/kg seems to be more effective compared to a total dose of 15-17 mg/kg. Further studies seem to be warranted.
Assuntos
Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Malária Falciparum/tratamento farmacológico , Mefloquina/uso terapêutico , Plasmodium falciparum/efeitos dos fármacos , Sesquiterpenos/uso terapêutico , Administração Retal , Animais , Artemisininas/administração & dosagem , Artesunato , Criança , Pré-Escolar , Combinação de Medicamentos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Equador , Feminino , Humanos , Masculino , Sesquiterpenos/administração & dosagem , Resultado do TratamentoRESUMO
In this study, we tested the polymerase chain reaction (PCR)-method to diagnose cutaneous leishmaniasis (CL) by taking exudate materials from lesions with cotton swabs, using our previously tested (PCR) panel comprised of Leishmania (Viannia) panamensis, L. (V.) braziliensis, L. (V.) guyanensis, L. (Leishmania) mexicana and L. (L.) amazonensis. The objectives of the present study were to improve the sampling method convenient for the patients and to test the usefulness of samples taken with cotton swabs. Sixteen patients were clinically diagnosed to have CL including one case of diffuse cutaneous leishmaniasis (DCL) in Ecuador and the causative Leishmania parasites were identified by PCR. All the 12 samples from CL patients of La Mana, positive for Leishmania DNA, were identified as L. (V.) panamensis, while two from CL of Huigra and one from DCL of San Ignacio were L. (L.) mexicana. In the field condition, taking biopsy material is not only painful but sometimes causes iatrogenic bacterial infections. Considering the sensitivity of the test, and convenient sampling procedure, it may be suggested that collection of exudates using cotton swabs may be a better alternative to biopsy sample for PCR-diagnosis of CL.
Assuntos
Leishmania/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Reação em Cadeia da Polimerase/métodos , Adulto , Animais , Criança , Pré-Escolar , DNA de Protozoário/análise , Equador , Exsudatos e Transudatos/parasitologia , Feminino , Humanos , Lactente , Leishmania/genética , Masculino , Sensibilidade e Especificidade , Úlcera Cutânea/diagnóstico , Úlcera Cutânea/parasitologiaAssuntos
Leishmaniose Cutânea/diagnóstico , Reação em Cadeia da Polimerase/métodos , Adolescente , Adulto , Animais , Biópsia/métodos , Criança , Equador , Feminino , Humanos , Leishmania guyanensis/isolamento & purificação , Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/parasitologia , MasculinoRESUMO
Molecular karyotypes of Leishmania isolates from patients with cutaneous leishmaniasis in Ecuador were analyzed by pulsed-field gel electrophoresis (PFGE) and Southern blot hybridization. The DNA karyotypes of L. major-like parasites were similar between two human isolates from a lowland coastal and a highland Andean region, but were apparently different from those of eleven World Health Organization reference strains including L. major. The smallest chromosome of 240 kilobases in L. major-like parasites was found to belong to the 715-class of small linear chromosomal DNAs, which have been shown to appear in some lines of Leishmania. Chromosome banding patterns of L. mexicana isolates exhibited a novel, ordered, chromosomal ladder, and were identical among four human isolates and one canine isolate from a restricted geographic region in the Andes. On the other hand, minor chromosome size polymorphisms were observed among three L. panamensis isolates from different endemic regions near the Pacific Coast. Chromosomal locations of dihydrofolate reductase-thymidylate synthetase and P-glycoprotein genes revealed further differences in chromosomal organizations among these Leishmania species in Ecuador. These results indicate that karyotype analysis by PFGE is useful for epidemiologic studies of leishmaniasis in Ecuador.
Assuntos
DNA de Protozoário/análise , Leishmania mexicana/genética , Leishmania tropica/genética , Leishmania/genética , Leishmaniose Cutânea/parasitologia , Animais , Southern Blotting , Sondas de DNA , Equador , Eletroforese em Gel de Ágar , Genes de Protozoários , Humanos , Cariotipagem , Leishmania/classificação , Leishmania/enzimologia , Leishmania mexicana/classificação , Leishmania mexicana/enzimologia , Leishmania tropica/classificação , Leishmania tropica/enzimologia , Tetra-Hidrofolato Desidrogenase/genética , Timidilato Sintase/genéticaRESUMO
Characterization is given of a new parasite, Leishmania equatorensis sp. n., which was isolated from the viscera of a sloth (Choloepus hoffmanni) and a squirrel (Sciurus granatensis), captured in humid tropical forest on the Pacific Coast of Ecuador. Data based on biological and molecular criteria, as well as numerical zymotaxonomical analysis, indicate that this parasite is a new species of the L. braziliensis complex. L. equatorensis is clearly distinguishable from all other known species within this complex, using the following molecular criteria: reactivity patterns with specific monoclonal antibodies, isoenzyme electrophoresis, and restriction-endonuclease fragment patterns of kinetoplast DNA (k-DNA).
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Leishmania/classificação , Sciuridae/parasitologia , Bichos-Preguiça/parasitologia , Animais , Anticorpos Monoclonais , DNA de Protozoário/análise , Equador , Eletroforese em Gel de Poliacrilamida , Leishmania/enzimologia , Leishmania/isolamento & purificaçãoRESUMO
The plebotomine sand fly fauna of Ecuador was surveyed in two 3-month collecting trips made in 1988 and 1990. A total of 12 provinces were visited, including three (Bolivar, Loja and Morona Santiago) from wich no previous records to phlebotomines existed. Forty-six species were collected, 13 of wich, together with 1 subspecies and 1 genus (Warileya) represented new records for the country. This survey increases the known number of species in Ecuador to 60. The distribuition of Ecuadorian sand flies is discussed in the light of these new findings
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Animais , Infecções por Bartonella/transmissão , Dípteros/parasitologia , Leishmaniose/transmissão , Psychodidae/parasitologia , EquadorRESUMO
In order to collect information on the role of Lutzomyia ayacuchensis in the transmission of leishmaniasis in a newly discovered Andean endemic focus in Ecuador, a longitudinal field study was carried out over 13 months. Monthly dissections were made of a minimum of 200 anthropophilic sandflies, collected at night during the month. A total of 2600 flies was separated from a small number of Lu. osornoi, another anthropophilic species in the area, and dissected; 95 (3.65%) were naturally infected with Leishmania mexicana promastigotes. The parasites were always located in the sandfly midgut. The current study revealed a marked monthly variation both in natural infections with Leishmania and in biting activity of sandflies in the endemic area, demonstrating a high transmission rate during the period from the early rainy season to the early or mid dry season (February to July).
Assuntos
Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/transmissão , Psychodidae/parasitologia , Animais , Equador , Feminino , Humanos , Estudos Longitudinais , Fatores de TempoRESUMO
Between 1986 and 1988, epidemiologic studies were carried out in a small rural community in an Andean region of Ecuador, where cutaneous leishmaniasis is highly endemic. A total of 25 human cases, positive for Leishmania parasites by culture and/or smear, were examined. Fourteen of the cases were in infants less than one year of age, suggesting intradomiciliary transmission of the disease. Clinically, many of these cases were similar to descriptions of "uta," a form of cutaneous leishmaniasis which occurs in Andean regions of Peru and is reported caused by L. peruviana. Of the 11 positive cultures obtained from human cases in the present study, eight were identified by molecular characterization as L. mexicana and three were identified as L. major-like. Two additional isolates of L. mexicana were also made from an infected dog and from a sand fly, Lutzomyia ayacuchensis, living in the region, thus implicating the latter species as possible reservoir and vector, respectively, of L. mexicana in this highland community. The significance and validity of recent isolates of L. major-like parasites from the New World are also discussed.