RESUMOEsta pesquisa teve como objetivo caracterizar a reprodução e o perfil hormonal dos esteróides sexuais do pirarucu, Arapaima gigas, além de validar um aspecto do dimorfismo sexual secundário. O experimento foi realizado na Fazenda Santo Antônio II, em Presidente Figueredo-AM, no período de fevereiro de 2004 a fevereiro de 2005. Foram selecionados 24 exemplares e divididos em três grupos de oito peixes (grupo "A", "B" e "C" com pirarucus de mais de quatro anos de idade, com três anos e dois anos, respectivamente). Os pirarucus foram estocados em três tanques de 400m 2 , um para cada grupo. Aspectos comportamentais, como o interesse por alimento, brigas, formação de casais e presença de ninhos, foram observados ao longo de todo o experimento. Amostras de sangue foram coletadas mensalmente, de todos os peixes, observou-se a presença de uma mancha alaranjada no macho como uma característica sexual secundária. Foram mensurados os níveis de testosterona (T), 17beta-estradiol (E 2 ) e 17alfa-hidroxi-progesterona (17aOHP) através de radioimunoensaio (RIA) de fase sólida. Todos os machos dos grupos "A" e "B" puderam ser identificados pela mancha alaranjada na região inferior da cabeça, corroborada pela concentração de testosterona, comprovando o conhecimento empírico dos ribeirinhos. Os níveis de T e E 2 nos peixes do grupo "A" e "B" tiveram maiores picos no início do período de chuva, enquanto que o 17aOHP teve oscilações constantes e pequenos picos no final do período chuvoso, os peixes do grupo "C" acompanharam essa tendência em concentrações menores. PALAVRAS-CHAVE: pirarucu, reprodução, esteróides sexuais, Arapaima gigas. Reproductive Aspects and Sexual Steroids Hormonal Profiles of Pirarucu, Arapaima gigas (SCHINZ,1822), in Captivity Conditions ABSTRACTThe purpose of this study was to characterize the growth, reproduction and hormonal profile of pirarucu, Arapaima gigas, and validate one sexual dimorphism characteristic. The experiment was carried in the fish farm Santo Antonio II, Presidente Figueredo city in the state of Amazonas -Brazil, from February 2004 to February 2005 In the experiment, 24 fishes were selected and divided in three groups, with eight fish in each one. The pirarucus from "A" group were older than four years. In "B" group the fishes were three years old and in "C" group these were two years old. The pirarucus were stocked in 400 m 2 excavated ponds, one pond for each group. Reproductive behavior like feeding interest, fights, pair formation and presence of nest were observed. Blood samples were taken monthly from all fishes during the experiment period, the sexual dimorphism characteristic was observed. Testosterone (T), 17b-estradiol (E 2 ) and 17ahidroxi-progesterona (17aOHP) levels were measured by radioimunoassay (RIA) in solid phase. All males of group "A" and "B" could be identified by an orange mark under the head, and the levels of T validated this data, proving the empirical knowledge of river men. T and E 2 levels of group "A" and "B" picked in the beginning of raining period an...

Os avanços tecnológicos têm aumentado o número de equipamentos elétricos e eletrônicos, seja nas residências ou mesmo no ambiente de trabalho, fazendo com que a população conviva com grande número de fontes de irradiação eletromagnética, com os mais diversos níveis de potência e freqüência. Por muitos anos, alguns cientistas e engenheiros acreditaram que o campo eletromagnético (CEM) com freqüência extremamente baixa não pudesse causar efeitos e alterações significantes no material biológico. O objetivo deste trabalho é verificar os possíveis efeitos adversos dos CEMs em humanos e animais, que foram publicados nos últimos anos, através de uma revisão da literatura disponível em Medline, revistas nacionais e internacionais e catálogos de obras de referência na área dos CEM (50/60 Hz). Como resultado foi observado que o CEM (50/60 Hz) é capaz de produzir diversos efeitos adversos em humanos e animais, como por exemplo: distúrbios na reprodução, doenças degenerativas, efeitos psiquiátricos e psicológicos, alterações citogenéticas, alterações no sistema cardiovascular, nervoso e neuroendócrino, bem como nos parâmetros biológicos e bioquímicos. Apesar de todas estas constatações e devido a muitas controvérsias entre vários autores, faz-se necessário um estudo mais específico e aprofundado sobre o assunto.

The development of experimental assays to study properties of herbal medicine is worthwhile. Vitex agnus castus (VAC) is utilized in popular medicine and some actions have been attributed to its extract. Blood cells (BC) and plasma proteins are labeled with technetium-99m (Tc-99m) and have been used in nuclear medicine, as in basic research. This procedure uses a reducing agent and stannous ion is utilized. There are reports that drugs can alter this labeling process. The aim of this work was to evaluate the influence of an aqueous extract of VAC on the labeling of blood constituents with Tc-99m. Blood was incubated with VAC, stannous chloride and Tc-99m, as sodium pertechnetate, and centrifuged. Samples of BC and plasma were separated, aliquots of BC and plasma were also precipitated with trichloroacetic acid to obtain soluble and insoluble fractions and the percentage of radioactivity (%ATI) was determined. The results show a statistical (p<0.05) alteration in the %ATI on blood compartments and on the insoluble fractions of plasma and BC. Probably, this extract would have chemical compounds with oxidant properties.
Modelos experimentais são relevantes no estudo de propriedades de plantas medicinais. Vitex agnus castus (VAC) é usado na medicina popular. Células sanguíneas (CS) e proteínas plasmáticas são marcadas com tecnécio-99m (Tc-99m) com aplicações na medicina nuclear e em pesquisa. Esse procedimento utiliza um agente redutor e o íon estanoso é usado. Drogas podem alterar esse processo de marcação. O objetivo desse trabalho foi avaliar a influência de um extrato aquoso de VAC na marcação de constituintes sanguíneos com Tc-99m. Sangue foi incubado com VAC, cloreto estanoso e Tc-99m, como pertecnetato de sódio e centrifugado. Amostras de CS e plasma foram separadas, alíquotas de CS e plasma foram também precipitadas com ácido tricloroacético para obtenção de frações solúvel (FS) e insolúvel (FI) e a percentagem de radioatividade (%ATI) foi determinada. Os resultados mostraram uma alteração estatística (p<0.05) na %ATI dos compartimentos sanguíneos e nas FI do plasma e CS. Provavelmente, esse extrato poderia ter compostos químicos com propriedades oxidantes

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This effect was probably due to products present in this drug that may complex with ions (Sn(+2) and 99mTcO4) or have a direct or indirect effect on intracellular stannous ion concentration.

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The aim of this study was to evaluate the influence of the proteic extract of R. communis on the cell physiology by the osmotic fragility, labeling of the blood elements with the 99mTc and cell morphology. To evaluate the osmotic fragility, the blood samples of the Wistar rats were incubated with the concentrations of R. communis and with the solutions of NaCl (0.4; 0.7; 0.9%). In the labeling of the blood elements procedure, the rat blood was treated with a solution of determining the rate of radioactivity (%ATI) in the plasma (P) and in the red blood cells (RBC). The soluble and insoluble fractions of the plasma were also evaluated. The cells morphology submitted to the extract was evaluated by the optical microscopy (x40

Doses of 60 Co gamma radiation with 2. 5; 5; 7.5; 10; 15; 20; 25; 30; 35; 40; 45; 50; 55; 60; 80; 160; 320 and 640 In order to study controversial aspects in B. straminea shell development following exposure to ionizing radiation, the growing behavior of this epidemiological vector of schistosomiasis after exposure to low intensity gamma rays was studied, in colonies (cross fertilization) and sexually segregated (self fertilization) situations. MATERIALS AND METHODSA population of 1,080 snails of B. straminea, BH breed obtained from Centro de Pesquisas Aggeu Magalhães-Fiocruz, was exposed to gammarays obtained from a 60 Co source receiving doses of 2. 5; 5; 7.5; 10; 15; 20; 25; 30; 35; 40; 45; 50; 55; 60; 80; 160; 320 and 640 Gy, applied to groups of 30 snails per dose. An additional group of 60 non irradiated (0 Gy) snails was kept as control.The mollusks were bred from eggs laid with a maximal difference of two days and were raised in laboratory for approximately 50 days. All snails were in a reproductive development stage.Fifty percent of the studied population was kept in colonies and the other half was maintained isolated in sexual segregation, allowing cross fertilization and self fertilization, respectively, in each set. Consequently, the snail in each groups/dose were placed in individual (isolated) and collective (colony) aquariums with the ratio of water volume/ snail (50 ml) kept constantly replenished with water (25°C ± 2°C and pH 6.6-6.8) during the period of observation.The irradiation of the snails by gamma-rays was done with groups of 30 snails held inside glass The embryological development of snails is particularly affected by ionizing radiation as stated by Liard et al. (1968), Okazaki et al. (1996), Melo et al. (1996) and Melo (1998). A previous report stated that following irradiation with gamma rays, a cessation in the development of the shell may occur (Perlowagora-Szumlewicz & Berry 1964). Snails of different ages showed the same shell diameter as observed by Rey (1967), Leal (1976), Rozenberg (1989) and Carvalho (1992 tubes by dose and placed in gamma-cell irradiator, model RL-60, from Radionics Laboratory, with dose rate of 0.97 Gy per minute. In order to avoid copulation during the exposure time, the snails were separated by a thin cotton cushion, in the isolated set of mollusks. The control group remained in a dark environment for the same time as the maximal (640 Gy) irradiation was applied in order to have the same conditions of temperature and humidity as those used in the irradiation procedure.The diameter was measured daily by means of a caliper applied to the major shell diameter, with the sites used for measuring marked with white ink. RESULTS