A nutrição para matrizes de frangos de corte tem como objetivo maximizar a produção de ovos e a qualidade da progênie subsequente e é considerada essencial para a melhora da produção e qualidade dos ovos. Os nutrientes transferidos para os ovos são importantes para o crescimento e desenvolvimento fisiológico do embrião. O organismo animal sofre constantemente ação do estresse oxidativo e o selênio (Se) é considerado um eficiente antioxidante natural que é essencial para matrizes de frangos de corte. Este estudo foi conduzido com matrizes de frango de corte alimentadas com duas fontes de Se (selenometionina - orgânica e selenito de sódio - inorgânico) para avaliar o seu desempenho produtivo, as características reprodutivas, a concentração de Se no ovo bem como o desempenho e rendimento de carcaça da progênie subsequente. Foram utilizadas 216 matrizes AP95 Aviagen de 55 a 65 semanas de idade, em delineamento inteiramente casualizado, com dois tratamentos e 27 repetições de quatro aves cada. Para o experimento com a progênie, foram utilizados 520 pintinhos mistos em delineamento inteiramente casualizado em um fatorial 2 x 2 (duas fontes de Se da dieta das matrizes e duas fontes de Se para dietas de frangos de corte - selenito de sódio e selenometionina) com quatro tratamentos, 13 repetições de 10 aves cada. As matrizes alimentadas com Se orgânico melhoraram a produção de ovos em comparação com o Se inorgânico (p = 0,038; p = 0,044). A concentração do Se no ovo e na clara foi maior para Se orgânico em comparação com o inorgânico (p <0,001; p <0,001). As taxas de fertilidade, bem como mortalidade embrionária, não sofreram efeito significativo ao se comparar as duas fontes. Não foram observadas diferenças entre a altura de albúmen, unidade Haugh e espessura da casca para a qualidade do ovo. O peso do ovo e coloração da gema foram estatisticamente diferentes (p=0,001; p=0,026) para fonte inorgânica comprada com a orgânica. A resistência a quebra do ovo foi melhor estatisticamente (p=0,007) para fonte orgânica. Não foram observadas interações entre a dieta da progênie e a dieta materna para nenhum dos critérios avaliados. Não foram observados efeitos da dieta materna, assim como da dieta da progênie sobre o consumo de ração, ganho de peso corporal e rendimento de carcaça e cortes. No entanto, a taxa de conversão alimentar foi melhor (p = 0,017) em frangos de corte provenientes de matrizes alimentadas com selenometiona. Assim, a selenometionina melhorou a produção e qualidade de ovos e propiciou maior transferência de Se para o ovo, principalmente na clara. Além disso, melhorou a conversão alimentar da progênie, devido a sua melhor biodisponibilidade. / The nutrition for broiler breeders has the objective of maximizing egg production and the quality of subsequent progeny. It is essential to improve the egg production and egg quality. The nutrients transferred to the eggs are important for growth and physiological development embryo. The animal organism is constantly suffering by oxidative stress. Selenium (Se) is considered an efficient natural antioxidant and has shown to be essential for broiler breeders. This trial was conducted using broiler breeders fed with two different sources of Se (organic - selenomethionine and inorganic - sodium selenite) to determinate performance, reproductive characteristics, Se concentration in egg as well as performance and carcass yield of the subsequent progeny. It was used 216 AP95 Aviagen broiler breeders, from 55 to 65 weeks of age, in completely randomized design with two treatments and 27 replications of four birds each. For subsequent progeny, it was used 520 straght-run chicks in a completely randomized design in a 2 x 2 factorial (two sources of Se for broiler breeders diets and two sources of Se for broilers diets- sodium selenite and selenomethionine) with four treatments and 13 replications of 10 birds each. Broiler breeders fed with organic Se had improved egg production in comparison to inorganic Se (p=0.038; p=0.044). Se concentration in whole egg and white egg were higher for organic Se in comparison to inorganic Se (p<0.001; p<0.001). The fertility and embryonic mortality were not significant between Se sources. No difference were observed to albumin height, Haugh unit and shell thickness for egg quality. The egg weight and yolk color were statistically different (p = 0.001; p = 0.026) for inorganic source compering to organic. The egg breaking was statistically better (p=0.007) for organic source. For progeny, no interactions between broiler diet and the maternal diet were observed for any of the criteria measured. No effect of maternal diet as well as broiler diet differences were observed on feed intake, body weight gain and carcass yield and cuts. However, feed conversion ratio was improved (p=0,017) in broiler from breeders fed selenomethione. Thus, selenomethionine has improved the egg production and quality, and has been transferred to the egg mainly in the egg white. Also, selenomethionine has improved feed conversion ratio because has a higher bioavailability.

O selênio durante a fase fetal e na lactação é de vital importância para o correto desenvolvimento dos sistemas imunológico, muscular e antioxidante dos potros. Existe pouca informação na literatura a qual seria a melhor fonte e o melhor momento para suplementar eqüino, assim como qual o grau de transferência placentária ou colostral. O presente estudo teve como objetivo avaliar a capacidade de transferência placentária e colostral de duas fontes dietéticas de selênio, utilizando como parâmetros os níveis plasmáticos de éguas e potros, e do colostro e do leite. Foram utilizadas 24 éguas gestantes, divididas em três grupos iguais e distribuídas seguindo um delineamento inteiramente casualizado. Grupo I suplementado por via oral com selenito de sódio como fonte inorgânica, grupo II suplementado por via oral com selenometionina como fonte orgânica, e grupo III controle, sem suplementação. A suplementação teve início no último terço da gestação até o sétimo dia pós-parto. Foram colhidas amostras de sangue das éguas, no dia do inicio do teste e no dia do parto, dos potros do nascimento e sétimo dia, e do leite no primeiro e sétimo dia pós-parto. A quantidade de selênio no colostro foi maior (p<0,05) no grupo suplementado com selenito de sódio (59,18 ± 14,5) quando comparada ao grupo do selenometionina (24,27 ±15,9). No plasma dos potros foi observada uma maior (p<0,05) presença de selênio naqueles animais do grupo suplementado com selenito de sódio (61,7 ± 34,4), quando comparada ao grupo do selenometionina (36,7 ± 17,3). Foi possível concluir que o selenito de sódio apresenta maior taxa de transferência placentária e colostral que o selenometionina, resultando em níveis colostrais e plasmáticos maiores, tanto nas éguas quanto nos potros. / Selenium is of vital importance for the correct development of immunologic, muscular and antioxidant systems of foals. There is not much information in literature about the best source and the best moment to supplement equines as well as to the level of placenta and colostrums transference. The objective was evaluate the capacity of placenta and colostrums transference of two dietetic sources of selenium, using plasma levels of mares and foals and colostrums and milk as parameters. Twenty four pregnant mares were studied, divided in three equal groups and distributed according to randomized design. Group I was supplemented with sodium selenite as inorganic source, group II was supplemented selenometionine as organic source, in equal quantities, from the beginning of the last third of gestation until the seventh day after birth and group III was control. The quantity of selenium in the colostrums was higher (p<0,05) in the group supplemented with sodium selenite (59,18 ± 14,5) when compared to the selenometionine group (24,27 ±15,9). In the plasma of foals it was observed a higher (p<0,05) presence of selenium than in those animals of the group supplemented with sodium selenite (61,7 ± 34,4) when compared to the selenometionine group (36,7 ± 17,3). The results of this study are that the sodium selenite presents higher taxe of placenta and colostrums transference than selenometionine, resulting in higher colostrums and plasmatic levels in mares and foals.

<p>Interaction between mercury and selenium has previously been observed both in man and in animals. The aim of this work was to study expressions of interaction between mercury and selenium in human K-562 cells. Inorganic and organic forms of mercury and selenium were used and cells were either pre-treated with selenium or simultaneously exposed to selenium and mercury. Concentrations of selenium and mercury chosen were indicated by a study of growth inhibition in the individual compounds: a low concentration of selenium and selenomethionine induced slight cell growth inhibition, while a high concentration resulted in a notable growth inhibition. Two mercury concentrations were chosen: one with minimal toxicity and another with high cell toxicity. In addition, uptake and retention patterns of selenomethionine and selenite differed in both selenocompounds.</p><p>All simultaneous treatments with 3.5 μM methylmercury produced a reduction in cellular mercury with increased selenium concentration. This was particularly obvious in selenite treatments. Growth curves from the simultaneous 3.5 μM methylmercury and selenite treatments indicated protection with increased selenite concentrations. In both exposure protocols, the 5 μM methylmercury treatments were toxic to the cells. </p><p>In both study protocols, cells exposed to selenite and mercuric chloride manifested increased cellular mercury uptake with increased selenium concentration. In all selenite and 35 μM mercuric chloride treatments, no inhibition of growth was observed, while the 50 μM mercuric chloride treatments were toxic to the cells. Selenite-dependent protection was achieved in both exposure protocols when considering the cellular uptake of mercury. With few exceptions, selenomethionine produced similar effects as selenite on mercuric chloride uptake and growth inhibition.</p>

Interaction between mercury and selenium has previously been observed both in man and in animals. The aim of this work was to study expressions of interaction between mercury and selenium in human K-562 cells. Inorganic and organic forms of mercury and selenium were used and cells were either pre-treated with selenium or simultaneously exposed to selenium and mercury. Concentrations of selenium and mercury chosen were indicated by a study of growth inhibition in the individual compounds: a low concentration of selenium and selenomethionine induced slight cell growth inhibition, while a high concentration resulted in a notable growth inhibition. Two mercury concentrations were chosen: one with minimal toxicity and another with high cell toxicity. In addition, uptake and retention patterns of selenomethionine and selenite differed in both selenocompounds. All simultaneous treatments with 3.5 μM methylmercury produced a reduction in cellular mercury with increased selenium concentration. This was particularly obvious in selenite treatments. Growth curves from the simultaneous 3.5 μM methylmercury and selenite treatments indicated protection with increased selenite concentrations. In both exposure protocols, the 5 μM methylmercury treatments were toxic to the cells. In both study protocols, cells exposed to selenite and mercuric chloride manifested increased cellular mercury uptake with increased selenium concentration. In all selenite and 35 μM mercuric chloride treatments, no inhibition of growth was observed, while the 50 μM mercuric chloride treatments were toxic to the cells. Selenite-dependent protection was achieved in both exposure protocols when considering the cellular uptake of mercury. With few exceptions, selenomethionine produced similar effects as selenite on mercuric chloride uptake and growth inhibition.

The objective of this study is to understand the petrographical, mineralogical and geochemical characteristics of Messinian (Upper Miocene) gypsum occurence in Polatli Sazilar region, Ankara and to determine the impurities associated with gypsum. Moreover, it is aimed to interpret the usability of this raw material with impurities in plaster and plasterboard production based on industrial standards. Based on petrographical study, the first variety of gypsum which have different physical properties is white massive, micro crystalline, and translucent gypsum. Prismatic, transparent, idiomorphic and cleavage dominated selenite is the second variety. The gypsum rock is also identified that it is composed of sand sized selenite crystals and gypsum grains in a calcite and clay rich matrix. These impurity minerals also observed in thin beds alternating with gypsum. Scanning electron microscopic (SEM) studies are conducted to determine the relationship between the impurity mineral, gypsum and the selenite. X-ray diffractometry (XRD) studies were used to identify the type of clay minerals. In the samples, Ca-smectite is the essential impurity clay mineral. Rarely, mixed layer of illite-smectite is also identified. Geochemical studies also shows that as the amount of clay impurity increases, MgO, Al2O3, Fe2O3, Na2O, K2O (wt%) increases with decreasing SO3 (wt%). On the other hand, impurity of calcite controls the CaO (wt%) content in varying amounts. Five different groups of samples indicating different abundance of clay and calcite impurities are interpreted. The clay rich samples are enriched, in general, in vanadium, nickel, copper and chromium.

Surface complexation models (SCMs) have proven to be a useful tool in predicting ion adsorption at the mineral – water interface. In particular, previous research has shown that the Diffuse Layer Model (DLM), Constant Capacitance Model (CCM), and Triple Layer Model (TLM), are all capable of predicting ion adsorption in relatively simple single solute systems. To better simulate the environmental conditions experienced by groundwater sources present in the Earth’s subsurface, experimental adsorption studies have been conducted for more complex multi-solute systems. Under these conditions, SCMs have not proven to be reliable in consistently predicting ion adsorption behavior for the adsorbates of interest. This inability of these SCMs to predict ion adsorption for more complex, multi-solute systems is thought to stem from the variable site density (NS) values utilized in these models. In this research, a methodology was developed for characterizing mineral surface heterogeneity that allows for the different site density values predicted from crystallography, microscopic imaging, tritium exchange, surface saturation data, and surface charging data to all be explained using a single unified theory. This methodology was applied to a goethite mineral sample used in performing batch adsorption studies in single and bi-solute systems with Cd(II), Pb(II), and Se(IV). The adsorption behavior of these adsorbates onto the goethite sample was successfully predicted using the Charge Distribution Multi-Site Complexation (CD-MUSIC) Model and surface complexes consistent with spectroscopic data and computational molecular modeling simulations. A second, separate modeling study was performed using CD-MUSIC to predict Hg(II) adsorption onto different goethite samples of varying size and crystal morphology in single and multi-solute systems. In this study, site density values were predicted for the mineral samples studied utilizing a linear relationship observed for goethite between specific surface area and proton reactive site density. The CD-MUSIC model proved successful in predicting Hg(II) adsorption over all conditions studied while employing only surface complexes consistent with molecular scale analyses. In addition, a novel method for quantifying carbonate’s presence in experimental systems was developed. / text

Στόχος της παρούσας μελέτης ήταν να διερευνηθεί η επίδραση αρχικά του σεληνιώδους νατρίου και κατόπιν του εκχυλίσματος των στύλων του Crocus sativus στον καταρράκτη, καθώς και σε βιοχημικές παραμέτρους του φακού, του ήπατος και διαφορετικών εγκεφαλικών περιοχών νεογνών επίμυων. Συγκεκριμένα, προσδιορίστηκε η αντιοξειδωτική ικανότητα και η συγκέντρωση του περιεχόμενου ασκορβικού οξέος του φακού, του ήπατος, του εγκεφαλικού φλοιού και της παρεγκεφαλίδας, ενώ μελετήθηκε και η υπεροξείδωση λιπιδίων των παραπάνω περιοχών. Επιπλέον, πραγματοποιήθηκε και συγκριτική μελέτη των εγκεφαλικών περιοχών των επίμυων-μαρτύρων ως προς την αντιοξειδωτική τους ισχύ και την απόκρισή τους στο οξειδωτικό στρες. / Impact of Crocus sativus stigmas' extract in selenite-induced rats.

No description available.

Kadmis yra plačiai paplitęs aplinkos teršalas. Šis sunkusis metalas yra pavojingas žmonių sveikatai. Tuo tarpu cinkas ir selenas yra būtini elementai žmonėms ir gyvūnams. Todėl šio darbo tikslas buvo įvertinti kadmio, cinko ir selenito jonų ūmų poveikį baltymų sintezės sistemos ir jos komponentų bei ląstelių antioksidacinės sistemos aktyvumams laboratorinių pelių kepenyse. Tikslui pasiekti iškelti šie uždaviniai: įvertinti ūmų kadmio jonų poveikį baltymų sintezės sistemai pelių kepenyse, transliacijos sistemos komponentų – tRNR bei aminoacil-tRNR sintetazės – aktyvumams, metalotioneino koncentracijai pelių kepenyse, redukuoto glutationo koncentracijai ir lipidų peroksidacijai pelių kepenyse bei eritrocituose ir įvertinti cinko ir selenito jonų įtaką pelių baltymų sintezės ir antioksidacinėms sistemoms, esant ūmiam kadmio jonų poveikiui. Tyrimo rezultatai parodė, kad kadmio jonų poveikis baltymų sintezės procesui pelių kepenyse susijęs su tiesioginiu poveikiu šiame procese dalyvaujančių komponentų – tRNR bei aminoacil-tRNR sintetazės – aktyvumų pokyčiais. Be to, kadmio jonai keitė ląstelių antioksidacinės sistemos komponentų (redukuoto glutationo ir metalotioneino) koncentracijas ir aktyvino lipidų peroksidaciją pelių kepenyse. Cinko ir selenito jonai apsaugojo transliacijos ir antioksidacinę sistemas nuo toksinio kadmio jonų poveikio. / Cadmium is a widespread environmental pollutant. This heavy metal forms a serious hazard to the public health. Zinc and selenium are essential elements for humans and animals. So, the aim of present study was to evaluate the acute effects of cadmium, zinc, and selenite ions on the effectiveness of protein synthesis system and its components in the liver of laboratory mice as well as on the activity of cellular antioxidant system. The objectives of the study were to evaluate the effects of cadmium ions on the rate of liver protein synthesis, on the activities of components of translation machinery – tRNA and aminoacyl-tRNA synthetase, on the content of metallothionein in the liver, on the content of reduced glutathione and lipid peroxidation in the liver and red blood cells; to evaluate the influence of zinc and selenite ions on the protein synthesis system and antioxidative system of mice affected by cadmium ions. The obtained results showed, that the toxicity of cadmium ions on hepatic protein synthesis is related to the changes in activities of the key components of protein synthesizing system – tRNAs and aminoacyl-tRNA synthetases. Moreover, cadmium ions altered the content of antioxidant components (reduced glutathione, metallothionein) and activated liver lipid peroxidation. Mice pre-treatment with zinc and selenite ions prevented both translational machinery and antioxidative system against cadmium-induced disturbances.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.