Parâmetros ósseos de codornas de corte suplementadas com diferentes níveis de vitamina A, de 15 a 35 dias de idade / [Parameters of bone of meat-type quail supplemented with different levels of vitamin A from 15 to 35 days of age]

Avaliou-se o efeito da utilização de níveis crescentes de vitamina A sobre os parâmetros ósseos de codornas de corte de 15 a 35 dias de idade. Foram utilizadas 1520 codornas, não sexadas, com peso médio inicial de 85±4,25g, distribuídas em um delineamento inteiramente ao acaso, totalizando oito tratamentos com cinco repetições e 38 codornas por unidade experimental. Os tratamentos consistiram de oito níveis de suplementação de vitamina A (0; 4.500; 6.000; 7.500; 9.000; 10.500; 12.000 e 13.500UI/kg da dieta). O período experimental foi de 15 a 35 dias de idade. Os ossos analisados apresentaram uma redução linear para o índice de Seedor, resistência óssea e teor de cinzas do fêmur e da tíbia de acordo com os níveis de suplementação de vitamina A. A suplementação de vitamina A para codornas de corte de 15 a 35 dias de idade mostrou resultados negativos para a qualidade óssea, com a necessidade de mais estudos sobre seu antagonismo com a vitamina D.(AU)

This study evaluated the effect of using increasing levels of vitamin A on bone parameters in meat-type quails from 15 to 35 days old. A total of 1520 unsexed quail with an average initial weight of 85g distributed in a completely randomized design, totaling eight treatments with five replicates and 38 quails per experimental unit were used. The treatments consisted of eight vitamin supplementation levels A (0; 4,500; 6,000; 7,500; 9,000; 10,500; 12,000 and 13,500IU / kg diet). The experimental period was 15 to 35 days of age. The bones analyzed showed a linear reduction to the Seedor index, bone strength and ash content of the femur and tibia according to vitamin supplementation levels Vitamin A supplementation for cutting quails from 15 to 35 days of age showed negative results for bone quality, with the need for more studies on its antagonism to vitamin D.(AU)

Níveis de suplementação de vitamina K para codornas de corte em crescimento de 15 a 35 dias de idade / Vitamin K supplementation for meat quail in growth of 15 to 35 days old

O presente experimento foi realizado com o objetivo de determinar os níveis de suplementação de vitamina K para codornas de corte. O delineamento experimental foi inteiramente ao acaso, com oito tratamentos, cinco repetições e 38 codornas por unidade experimental. Os níveis de suplementação de vitamina K foram: 0; 0,7; 1,0; 1,3; 1,6; 1,9; 2,2; 2,5mg/kg de ração. Não houve influência dos níveis de suplementação de vitamina K sobre o consumo de ração, peso corporal, ganho de peso, biomassa corporal acumulada e conversão alimentar, como também não foram alterados o peso, a densidade óssea, a resistência óssea e a concentração de cinzas no fêmur e na tíbia, o comprimento e o índice de Seedor do fêmur e o diâmetro da tíbia. O diâmetro e a concentração de cálcio no fêmur bem como o comprimento e a concentração de cálcio na tíbia responderam de forma quadrática (P<0,05), sendo os melhores níveis encontrados de 1,33; 1,42; 1,59 e 1,42mg de vitamina K, respectivamente. O tempo de protrombina, a concentração de cálcio no soro e a fosfatase alcalina também não foram afetados significativamente. Conclui-se que os níveis de suplementação não influenciaram o desempenho, portanto rações à base de milho e farelo de soja são suficientes para atender às necessidades de vitamina K das codornas nessa fase.(AU)

An experiment was carried out in order to determine the levels of vitamin K for meat quails. The experimental design was completely randomized with 8 treatments, 5 repetitions and 38 quails per experimental unit. The levels of vitamin K supplementation were 0; 0.7; 1.0; 1.3; 1.6; 1.9; 2.2; 2.5 mg/kg diets. There was no influence in the levels of vitamin K supplementation on feed intake, body weight, weight gain, biomass accumulated body and feed conversion. It also didn't affect the weight, bone density, bone strength and concentration of ash in the femur and tibial, length, index of Seedor femur and tibial diameter. Femur diameter and femur calcium concentration and the tibial length and tibial calcium concentration showed a quadratic response, with the highest levels found 1.33; 1.42; 1.59 and 1.42 mg of vitamin respectively. Prothrombin time, concentration of serum calcium and alkaline phosphatase levels also were not significantly affected. In conclusion, levels of supplementation did not influence the performance of meat quails, so diets based on corn and soybean meal are sufficient to meet the needs of the meat quails at this stage.(AU)

Exigência de valina e isoleucina para codornas de corte no período de um a 14 dias e de 15 a 35 dias de idade / Valine and isoleucine requirement for meat quails in the period of 1 to 14 days and of 15 to 35 days old

Foram conduzidos dois experimentos, com o objetivo de estimar a exigência de valina e isoleucina digestível para codornas de corte em crescimento. No experimento 1, foram utilizadas 2.160 codornas de corte de um dia de idade, não sexadas, distribuídas em um delineamento inteiramente ao acaso, com arranjo fatorial 4x4, sendo quatro níveis de valina digestível (0,90, 1,10, 1,30 e 1,50%) e quatro níveis de isoleucina digestível (0,80, 1,00, 1,20 e 1,40%), totalizando 16 tratamentos, com três repetições e 45 codornas por unidade experimental. O peso corporal, o ganho de peso e a biomassa corporal acumulada aumentaram linearmente em função dos níveis de valina digestível e foram influenciados de forma quadrática, estimando 1,38% de isoleucina digestível. No experimento 2, foram utilizadas 1.440 codornas de corte não sexadas, distribuídas em um delineamento inteiramente ao acaso, com arranjo fatorial 4x4, sendo quatro níveis de valina digestível (0,82, 1,02, 1,22 e 1,42%) e quatro níveis de isoleucina digestível (0,73, 0,93, 1,13 e 1,33%), totalizando 16 tratamentos, com três repetições e 30 codornas por unidade experimental. O desempenho de codornas de corte, no período de 15 a 35 dias de idade, não foi influenciado pelo aumento dos níveis de valina e isoleucina digestível nas rações experimentais. Conclui-se que as exigências de valina e isoleucina digestível para o máximo desempenho de codornas de corte, no período de um a 14 dias de idade, foram de 1,50% e 1,38%, respectivamente, correspondendo às relações valina:lisina de 95% e isoleucina:lisina de 88%. Os menores níveis avaliados, no período de 15 a 35 dias de idade, de 0,82% de valina digestível e de 0,73% de isoleucina digestível, correspondendo às relações valina:lisina de 52% e isoleucina: lisina de 46%, foram suficientes para satisfazer as exigências nutricionais das codornas de corte sem comprometer o desempenho.(AU)

Two experiments were carried out in order to estimate the requirements of digestible valine and isoleucine for growing meat quails. In experiment 1, 2160 meat quails with 1 day of age, not sexed, were used, distributed in a completely randomized design with a 4x4 factorial arrangement, with four levels of digestible valine (0.90, 1.10, 1.30, and 1.50%) and four levels of digestible isoleucine (0.80, 1.00, 1.20, and 1.40 %), totaling 16 treatments with three replications and 45 quails per experimental unit. The body weight, the weight gain, and the accumulated body biomass linearly increased in function of digestible valine levels and were influenced in a quadratic way estimating 1.38% of digestible isoleucine. In experiment 2, 1440 meat quails, not sexed, were used, distributed in a completely randomized design with a 4x4 factorial arrangement, with four levels of digestible valine (0.82, 1.02, 1.22, and 1.42%) and four levels of digestible isoleucine (0.73, 0.93, 1.13, and 1.33%), totaling 16 treatments with three replications and 30 quails per experimental unit. The performance of meat quails from 15 to 35 days of age was not affected by increased levels of digestible valine and digestible isoleucine in the experimental diets. It was concluded that the requirements of digestible valine and digestible isoleucine for maximum performance of meat quail from one to 14 days of age were 1.50% and 1.38%, respectively, corresponding to relations: valine: lysine of 95% and isoleucine: lysine of 88%. The lower levels evaluated, in the period of 15 to 35 days old, 0.82% digestible valine and 0.73% of digestible isoleucine, corresponding to relations valine: lysine of 52% and isoleucine: lysine of 46% were sufficient to meet the nutritional requirements of meat quails without compromising performance.(AU)

Introduced species in the Pantanal: implications for conservation.

Land use and human occupation within the natural habitats of the Pantanal have facilitated introduction of invasive species of plants and animals, including domestic species. Exotic species threaten regional biodiversity because they modify ecological community structure, alter natural habitats and affect local biodiversity. An international organisation, the International Union for Conservation of Nature (IUCN), and the Brazilian government, identify invasive species as the third most important threat to biodiversity, following habitat loss and direct effect on species. In addition, exotic species carry pathogens or may function as vectors or reservoirs for diseases that affect regional biota.

Introduced species in the Pantanal: implications for conservation

Land use and human occupation within the natural habitats of the Pantanal have facilitated introduction of invasive species of plants and animals, including domestic species. Exotic species threaten regional biodiversity because they modify ecological community structure, alter natural habitats and affect local biodiversity. An international organisation, the International Union for Conservation of Nature (IUCN), and the Brazilian government, identify invasive species as the third most important threat to biodiversity, following habitat loss and direct effect on species. In addition, exotic species carry pathogens or may function as vectors or reservoirs for diseases that affect regional biota.

O uso da terra e a ocupação humana nos hábitats naturais do Pantanal têm facilitado a introdução de espécies invasivas de plantas e animais, incluindo espécies domésticas. As espécies exóticas ameaçam a biodiversidade regional porque modificam a estrutura das comunidades ecológicas, alteram hábitats e afetam a biodiversidade. A organização internacional União Internacional para a Conservação da Natureza (IUCN) e o Governo brasileiro identificam as espécies invasoras como a terceira maior ameaça para a biodiversidade, seguida da perda de hábitat e do efeito direto sobre espécies. Além disso, espécies exóticas são portadoras de patógenos ou podem funcionar como vetores ou reservatórios de doenças que afetam a biota.

Factores sociodemográficos asociados al antecedente de aborto inducido en cuatro centros de salud de la ciudad de Lima - Perú / Sociodemographic factors associated with background of induced abortion in four health centers in the city of Lima - Peru

Se realizó un estudio descriptivo en 552 mujeres que se habían sometido al aborto inducido. El trabajo se hizo en los centros de salud de Chosica, el Agustino, el centro de Lima y el Hospital Cayetano Heredia durante los años 1999-2003. El objetivo era identificar factores sociodemográficos asociados al aborto inducido en algunos centros de salud de la ciudad de Lima, además de investigar complicaciones médicas según los autores que lo practicaron. La totalidad de mujeres estaban en la edad reproductiva; el 61 por ciento tenía instrucción secundaria completa o superior; el 66 por ciento en unión estable (casadas y convivientes). Habían iniciado su actividad sexual en la adolescencia un 74 por ciento y en esta misma etapa interrumpieron su embarazo un 23 por ciento. Hubieron en total 828 abortos inducidos, 59 por ciento fueron practicados pasado el mes de amenorrea y más de tres meses el 3.26 por ciento. De total de las 552 mujeres un 41 por ciento había interrumpido su primera gestación por medio del aborto inducido. De lo manifestado de este grupo de mujeres, médicos fueron quienes más practicaron esta intervención 84 por ciento, mientras que los empíricos tuvieron mayor proporción de complicaciones 63 por ciento. Las complicaciones se presentaban en mayor proporción mientras mayor fue el tiempo de embarazo y menor el conocimiento médico de quien lo practicó. Razones para tomar la determinación de abortar, fueron la situación económica difícil para las casadas y convivientes, mientras que para las solteras fue el no estar unidad. Una gran mayoría 96 por ciento estaba consciente de que el aborto inducido ponía en peligro su salud, en la misma proporción conocían o habían usado anticonceptivos y sin embargo no tomaron precauciones por descuido 83 por ciento. Sentimientos de culpa poco o nada manifestaron 64 por ciento. Gran proporción manifestó ser creyente a predomino de las católicas 92 por ciento.

It was done a descriptive research in 552 women, who have submitted to an induced abortion. Research was done in Chosica’s Health center, Agustino’s Health center, Lima’s Health center and Cayetano Heredia Hospital since 1999-2003. The propose of this research, was identify sociodemographic factors associated to induce abortion in some Heath Centers around Lima City, also this research was done in order to indicate the medical complications by the same doctors who has done it. All of women were in reproductive age; 61 per cent of them have studied secondary until they finished or in some cases they have continued; 66 per cent of them live together with a partner in a faithful way (married or not married). They have started their sexual activity during adolescence in a 74 per cent, and at this same stage the interrupted their pregnancy in 23 per cent. There were in total 828 cases of induced abortion, 59 per cent of them were done some time later the month of amenorrhea, and 3.25 per cent were done after months. From 552 women as a total, 41 per cent have interrupted their first pregnancy by means of induced abortion. This group of women declares that, doctors were the ones who did this intervention in most of the cases 84 per cent. On the hand, interventions that have been done by empirics result in a high percent of complication 63 per cent. Complications seem to appear in a high rate if the time of pregnancy was long or if the medical knowledge was not enough in them who did this intervention. Some reasons to abort was the hard economy situation for them who live with a partner (married or not married), the single ones considered that beings alone was the reason. A high percent 96 per cent knew that induced abortion included some risks which could be harmful for their health the same percent of women knew or have used contraceptives. Nevertheless they did not take precaution because of oversight 83 per cent. Women felt a bit fault or non fault...

The toxicity of exposure to the organochlorine, dieldrin, at a sympathetic junction and on the skin of the frog, Caudiverbera caudiverbera.

The effects of the organochlorine, dieldrin, were tested on a noradrenergic synapse of the frog, Caudiverbera caudiverbera. Nerve stimulation induced a transient increase in short circuit current (SCC) and in the potential difference (PD), which consisted of a rapid and then a slow component. Dieldrin in the concentration range 0.01-1.0 mM caused a concentration-dependent block of both components to 32% of their control values, which was partially reversed by washout. In some experiments, this blocking effect was preceded by an initial increase in the magnitude of the electrical parameters of the nonstimulated skin and also in the synaptic response to stimulation when the lowest dieldrin concentration (0.01 mM) was applied; higher concentrations (0.1-1.0 mM) led to progressive reduction of the responses. Results are interpreted as a perturbation of the lipid bilayer structure, which affects the functionality of lipid-protein complexes, leading, on one hand, to glandular Cl- channel inactivation and epithelial Na+ channel blockade and, on the other hand, to transient glandular Cl- activation, opening of a putative Na+ channel, and subsequent blockade.

Toxic effects of the fungicide benomyl on cell membranes.

This paper examines the toxicity of the fungicide benomyl towards cell membranes. Approaches to this aim were the study of its acute effects on the stimulatory response of a frog neuroepithelial synapse and on membrane models. The latter consisted of large unilamellar vesicles of dimyristoylphosphatidylcholine (DMPC) and phospholipid multilayers built-up of DMPC and dimyristoylphosphatidylethanolamine (DMPE). Results showed that benomyl at concentrations as low as 10 microM decreased the stimulatory response of the potential difference (PD) and the short-circuit current (SCC) of the frog sympathetic junction. It is concluded that benomyl caused a dose-dependent reduction in the response of a sympathetic junction of the frog to stimulation leading to Cl(-) channel perturbation. This finding might be explained from those obtained from fluorescence spectroscopy and X-ray diffraction studies on membrane models. In fact, similar (0.01-1.0 mM) concentrations induced structural perturbations in DMPC large unilamellar vesicles and multilayers, respectively. Although it is still premature to define the precise molecular mechanism of benomyl toxicity, the experimental results confirm the important role played by the phospholipid bilayers in the interaction of the pesticide with cell membranes.

The organochlorine herbicide chloridazon interacts with cell membranes.

Chloridazon is a widely used organochlorine herbicide. In order to evaluate its perturbing effect on cell membranes it was made to interact with human erythrocytes, frog adrenergic neuroepithelial synapse and molecular models. These consisted in multilayers of dimyristoylphosphatidylethanolamine (DMPE) and of dimyristoylphosphatidyltidylcholine (DMPC), representative of phospholipid classes located in the inner and outer monolayers of the erythrocyte membrane, respectively. X-ray diffraction showed that chloridazon interacted preferentially with DMPC multilayers. Scanning electron microscopy revealed that 0.1 mM chloridazon induced erythrocyte crenation. According to the bilayer couple hypothesis, this is due to the preferential insertion of chloridazon in the phosphatidylcholine-rich external moiety of the red cell membrane. Electrophysiological measurements showed that nerve stimulation was followed immediately by a transient increase in short-circuit current (SCC) and in the potential difference (PD) of the neuroepithelial synapse. Increasing concentrations of chloridazon caused a dose-dependent and reversible decrease of the responses of both parameters to 76% of their control values. The pesticide induced a similar (28%) significant time-dependent decrease in the basal values of the SCC and of PD. These results are in accordance with a perturbing effect of chloridazon on the phospholipid moiety of the nerve fibre membrane leading to interference with total ion transport across the nerve skin junction.

Interaction of the organochlorine pesticide dieldrin with phospholipid bilayers.

Dieldrin is an organochlorine insecticide highly toxic for human beings. Although its exact mechanism of action is not well known, there is evidence that it acts at the cell membrane level. In fact, the lipophilicity of the pesticide as well as that of the phospholipid bilayer present in biological membranes makes the latter a most likely target for the interaction of dieldrin with living organisms. In order to evaluate its perturbing effect upon cell membranes the pesticide was made to interact with human erythrocytes and molecular models. These studies were performed by scanning electron microscopy on erythrocytes, fluorescence spectroscopy on dimyristoylphosphatidylcholine (DMPC) large unilamellar vesicles and X-ray diffraction on multilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE). It was observed that dieldrin particularly interacted with DMPC liposomes and multilayers perturbing its molecular arrangements. However, no effect was noticed on erythrocytes, which might be due to its high cholesterol content.

The organochlorine pesticide heptachlor disrupts the structure of model and cell membranes.

Heptachlor is an organochlorine pesticide which is particularly toxic for aquatic life. A significant source of this pesticide for infants is breast milk, where its concentration is considerably higher than in dairy milk. Given the lipophilic character of heptachlor, lipid-rich cell membranes are a very plausible target for its interaction with living organisms. In order to evaluate its toxicity towards cell membranes, heptachlor was made to interact with human erythrocytes and molecular models of the red cell membrane. These consisted of multilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), which are types of phospholipids that are respectively located in the outer and inner monolayers of the erythrocyte membrane, and large unilamellar vesicles (LUV) of DMPC. Observations by scanning electron microscopy showed that 10 mM heptachlor produced various degrees of shape alterations to erythrocytes, which ranged from a few blebs in some cells to a great number of protuberances in others. On the other hand, experiments performed by X-ray diffraction on DMPC and DMPE indicated that the bilayer structure of DMPC was much more affected by heptachlor than that of DMPE. Measurements by fluorescence spectroscopy on DMPC LUV confirmed the X-ray diffraction results in that both the hydrocarbon chain and polar head regions of DMPC were structurally perturbed by heptachlor. The results obtained from the model studies could explain the shape changes induced to red cells by heptachlor. According to the bilayer hypothesis, they were due to the preferential interaction of heptachlor with the phosphatidylcholine-rich external moiety of the erythrocyte membrane. It is therefore concluded that toxic effects of this pesticide can be related to its capacity to perturb the phospholipid bilayer structure, whose integrity is essential for cell membrane functions.

Evolution of the structural repertoire of the human V(H) and Vkappa germline genes.

Variable genes of human Ig are classified in families and clans which reflect the early events of gene duplication in the evolution of the locus. This organization in multiple copies of variable genes plus the somatic processes of recombination and hypermutation allows the immune system to generate an antibody repertoire of great diversity. At present the role that somatic processes play in the generation of that diversity is understood with some detail. It is a matter of hard controversy, however, which selective pressures have shaped the evolution of the germline genes of Ig and, consequently, what the role of this germline component in the generation of the antibody diversity actually is. Previous studies of our group have showed that the structural repertoire of Ig-determined by the canonical structures-is an important factor to determine the recognition properties of the antibodies. Complete knowledge of the sequences of the human V(H) and Vkappa loci is available to analyze the evolution of the structural repertoire of these loci. Two phylogenetic gene trees were built from the functional germline genes and the evolution of the structural repertoire was studied. We report that for both loci the canonical structures are not randomly distributed within the tree. Conversely, it is shown that the evolution of the structural repertoire follows a gradual process of diversification. This indicates a correlation between the evolution of genes and the structural repertoire, although important differences are found in the patterns of evolution of the structural repertoire between V(H) and Vkappa. Based on those results we propose a primordial structural repertoire for V(H) and Vkappa. The general properties and an outline of the three-dimensional structure of this primordial repertoire are given.

Interaction of 2,4-dichlorophenoxyacetic acid (2,4-D) with cell and model membranes.

2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, is a component of the "agent orange' whose toxicity has been extensively studied without definite conclusions. In order to evaluate its perturbing effect upon cell membranes, 2,4-D was made to interact with human erythrocytes and molecular models. These studies were performed by scanning electron microscopy on red cells, fluorescence spectroscopy on dimyristoylphosphatidylcholine (DMPC) large unilamellar vesicles and X-ray diffraction on multilayers of DMPC and dimyristoylphosphatidylethanolamine (DMPE). It was observed that 2,4-D induced a pronounced shape change to the erythrocytes. This effect is explained by the herbicide interaction with the outer monolayer of the red cell membrane.