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561.
Carotenoids in eggs and plasma of red-legged partridges: effects of diet and reproductive output 总被引:2,自引:0,他引:2
Bortolotti GR Negro JJ Surai PF Prieto P 《Physiological and biochemical zoology : PBZ》2003,76(3):367-374
Carotenoids are important dietary constituents in birds. They serve as pigments and play numerous physiological roles in both the laying hen and developing embryo. However, factors determining the absorption of carotenoids and their allocation to different functions are numerous and complex, and causal relationships are generally poorly known. Our objective was to determine the degree to which carotenoid levels in egg yolks and the plasma of hens were influenced by differences in diet and reproductive output in captive red-legged partridges. Carotenoid concentrations were measured by high performance liquid chromatography in two feeds (high and low carotenoid content) and in yolks and plasma of hens near the start and end of laying. Early in the laying season, plasma and yolk carotenoids varied with diet and were correlated with one another. Late in the season, a dietary effect was evident only for yolks, and there was no relationship between plasma and egg levels of individual hens. However, plasma carotenoids at the end of laying were strongly correlated with the number of eggs that had been laid. Dietary availability, although important, could explain some variation in carotenoid levels in plasma and egg yolks only in the context of reproductive history. 相似文献
562.
Sanchez-Mateos P de la Rosa G Longo N 《Nature medicine》2002,8(8):765; author reply 765-765; author reply 766
563.
Azurmendi A Braza F Sorozabal A García A Braza P Carreras MR Muñoz JM Cardas J Sánchez-Martín JR 《Hormones and behavior》2005,48(2):187-195
This study explores the potential relationship between a series of cognitive abilities and testosterone, dehydroepiandrosterone (DHEA), androstenedione, and body mass index (BMI) measurements in 5-year-old children. 60 boys and 69 girls were administered a test (K-BIT) which provided measurements of fluid intelligence (Matrices subtest), crystallized intelligence (Vocabulary subtest), and IQ composite (the combination of the two subtests); a sub-sample of 48 boys and 61 girls was also subjected to diverse tests related to theory of mind (affective labeling, appearance-reality distinction, display rules, and false belief). Testosterone, DHEA, and androstenedione levels were measured using an enzyme immunoassay technique in saliva samples. An analysis of variance failed to reveal any significant differences between boys and girls in any of the cognitive abilities assessed. The correlation analysis revealed a positive relationship between fluid intelligence and testosterone levels in boys, a negative relationship between crystallized intelligence and androstenedione levels in girls, and between affective labeling and androstenedione levels in boys. A multiple regression analysis indicated that androstenedione and BMI were the best predictors for some of the cognitive abilities assessed. 相似文献
564.
Payan F Leone P Porciero S Furniss C Tahir T Williamson G Durand A Manzanares P Gilbert HJ Juge N Roussel A 《The Journal of biological chemistry》2004,279(34):36029-36037
The xylanase inhibitor protein I (XIP-I) from wheat Triticum aestivum is the prototype of a novel class of cereal protein inhibitors that inhibit fungal xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). The crystal structures of XIP-I in complex with Aspergillus nidulans (GH10) and Penicillium funiculosum (GH11) xylanases have been solved at 1.7 and 2.5 A resolution, respectively. The inhibition strategy is novel because XIP-I possesses two independent enzyme-binding sites, allowing binding to two glycoside hydrolases that display a different fold. Inhibition of the GH11 xylanase is mediated by the insertion of an XIP-I Pi-shaped loop (Lalpha(4)beta(5)) into the enzyme active site, whereas residues in the helix alpha7 of XIP-I, pointing into the four central active site subsites, are mainly responsible for the reversible inactivation of GH10 xylanases. The XIP-I strategy for inhibition of xylanases involves substrate-mimetic contacts and interactions occluding the active site. The structural determinants of XIP-I specificity demonstrate that the inhibitor is able to interact with GH10 and GH11 xylanases of both fungal and bacterial origin. The biological role of the xylanase inhibitors is discussed in light of the present structural data. 相似文献
565.
566.
Oliva JM Ballesteros I Negro MJ Manzanares P Cabañas A Ballesteros M 《Biotechnology progress》2004,20(3):715-720
The inhibitory effects of various lignocellulose degradation products on glucose fermentation by the thermotolerant yeast Kluyveromyces marxianus were studied in batch cultures. The toxicity of the aromatic alcohol catechol and two aromatic aldehydes (4-hydroxybenzaldehyde and vanillin) was investigated in binary combinations. The aldehyde furfural that usually is present in relatively high concentration in hydrolyzates from pentose degradation was also tested. Experiments were conducted by combining agents at concentrations that individually caused 25% inhibition of growth. Compared to the relative toxicity of the individual compounds, combinations of furfural with catechol and 4-hydroxybenzaldehyde were additive (50% inhibition of growth). The other binary combinations assayed (catechol with 4-hydroxybenzaldehyde, and vanillin with catechol, furfural, or 4-hydroxybenzaldehyde) showed synergistic effect on toxicity and caused a 60-90% decrease in cell mass production. The presence of aldehydes in the fermentation medium strongly inhibited cell growth and ethanol production. Kluyveromyces marxianus reduces aldehydes to their corresponding alcohols to mitigate the toxicity of these compounds. The total reduction of aldehydes was needed to start ethanol production. Vanillin, in binary combination, was dramatically toxic and was the only compound for which inhibition could not be overcome by yeast strain assimilation, causing a 90% reduction in both cell growth and fermentation. 相似文献
567.
López Francisco Fungairiño Sara de las Heras Paloma Serrano José Acosta Francisco 《Plant Ecology》2001,157(1):13-21
Retama sphaerocarpa (L.) Boiss. is aMediterranean shrub with a remarkably simplified metameric structure. Terminalyoungest shoots act as units of modular growth, being able to produce newshootsby basal axillary buds (at the base of the shoot) and inflorescencesby lateral axillary buds. In this study, we have analysed the structural andgrowth potential features of these modules, as well as theirdemographic proportions, regarding the allocation of newvegetative and reproductive growth in plants of different age. Reproductiveeffort is proportionally higher in older plants. This shift in the allocationstrategy with plant ontogeny is not attained with changes in the shoot modules(which maintain a constant size, nutrient composition and show a similarnew growth investment per module) but through a differentdemographic composition of the population ofmodulesaccording to their developmental fate (vegetative or reproductive).This indicates a high level of iterativity and a purely modular growth, sincethe attributes of the individual (age of the plants) do not seem toaffect those of the integrating modular units (growth performance of theshoots). 相似文献
568.
Victor Pereira Paloma Carbajales Marta López-Alonso Marta Miranda 《Biological trace element research》2018,185(1):135-142
Environmental and occupational mercury exposure is considered a major public health issue. Despite being well known that MeHg exposure causes adverse effects in several physiologic functions, MeHg effects on salivary glands still not completely elucidated. Here, we investigated the cellular MeHg-induced damage in the three major salivary glands (parotid, submandibular, and sublingual) of adult rats after chronic, systemic and low doses of MeHg exposure. Rats were exposed by 0.04 mg/kg/day over 60 days. After that, animals were euthanized and all three glands were collected. We evaluated total Hg accumulation, metallothionein I/II (MT I/II), α-smooth muscle actin (α-SMA), and cytokeratin 18 (CK18) immune expression. Our results have showed that MeHg is able to disrupt gland tissue and to induce a protective mechanism by MT I/II expression. We also showed that cell MT production is not enough to protect gland tissue against cellular structural damage seen by reducing marking of cytoskeletal proteins as CK18 and α-SMA. Our data suggest that chronic MeHg exposure in low-daily doses is able to induce cellular damage in rat salivary glands. 相似文献
569.
Improving zinc accumulation in cereal endosperm using HvMTP1, a transition metal transporter 下载免费PDF全文
Paloma K. Menguer Thomas Vincent Anthony J. Miller James K.M. Brown Eva Vincze Søren Borg Preben Bach Holm Dale Sanders Dorina Podar 《Plant biotechnology journal》2018,16(1):63-71
Zinc (Zn) is essential for all life forms, including humans. It is estimated that around two billion people are deficient in their Zn intake. Human dietary Zn intake relies heavily on plants, which in many developing countries consists mainly of cereals. The inner part of cereal grain, the endosperm, is the part that is eaten after milling but contains only a quarter of the total grain Zn. Here, we present results demonstrating that endosperm Zn content can be enhanced through expression of a transporter responsible for vacuolar Zn accumulation in cereals. The barley (Hordeum vulgare) vacuolar Zn transporter HvMTP1 was expressed under the control of the endosperm‐specific D‐hordein promoter. Transformed plants exhibited no significant change in growth but had higher total grain Zn concentration, as measured by ICP‐OES, compared to parental controls. Compared with Zn, transformants had smaller increases in concentrations of Cu and Mn but not Fe. Staining grain cross sections with the Zn‐specific stain DTZ revealed a significant enhancement of Zn accumulation in the endosperm of two of three transformed lines, a result confirmed by ICP‐OES in the endosperm of dissected grain. Synchrotron X‐ray fluorescence analysis of longitudinal grain sections demonstrated a redistribution of grain Zn from aleurone to endosperm. We argue that this proof‐of‐principle study provides the basis of a strategy for biofortification of cereal endosperm with Zn. 相似文献
570.
Jordi A. Matias-Guiu Ana Cortés-Martínez Paloma Montero Vanesa Pytel Teresa Moreno-Ramos Manuela Jorquera Miguel Yus Juan Arrazola Jorge Matías-Guiu 《BMC neurology》2018,18(1):214