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821.
The behavioral and neuroprotective effects of 17beta-estradiol (E2), on ovariectomized rats treated with a subconvulsive dose (7 mg/kg bw, ip) of kainic acid (KA), were examined. Estradiol was administered either acutely (150 mug/rat, ip) along with KA, 14 days post-ovariectomy, or chronically (sc capsules providing proestrus estrogen levels in serum) starting at ovariectomy. Exploratory behavior, as deduced by sniffing in the open field test, was reduced in KA-treated rats. Both hormonal schemes partially restored sniffing behavior in KA-lesioned subjects. Moreover, acute and chronic E2 administration in KA-treated rats resulted in increased vertical and horizontal activity of these animals in the open field test. Memory for object recognition was reduced following KA and was not restored by hormonal treatments. Acute, but not chronic, E2 coadministration with KA significantly impaired spatial performance in the water maze task, while KA alone had no effect. Both acute and chronic estradiol administration rescued hilar and CA1 neurons from KA-induced cell death. Chronic, but not acute, E2 increased neurofilament immunoreactivity in the mossy fibers of the dentate gyrus neurons, similarly to KA. Our results show that although estradiol administration in KA-treated rats has beneficial effects on cell survival, it has diverse effects on exploratory behavior, object, and spatial memory. Estradiol effects on KA-lesioned animals depended on the duration and timing of exposure to the hormone, implying different mechanisms of hormone actions. 相似文献
822.
Mikulíková K Miksík I Deyl Z 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,815(1-2):315-331
Non-enzymatic posttranslational modifications of bovine serum albumin (BSA) by oxo-compounds, particularly glucose, ribose, glyoxal and glutardialdehyde, have been investigated using a set of modern chromatographic and electrophoretic separation methods. High-performance liquid chromatography (HPLC) alternatively with UV spectrophotometric (diode array) or mass spectrometric (MS) detection, polyacrylamide gel electrophoresis (PAGE) with Coomassie brilliant blue staining detection, and capillary zone electrophoresis (CZE) with UV spectrophotometric detection have been employed for the investigation of the chemical and structural changes of BSA caused by its reaction with the above oxo-compounds exhibiting different degree of reactivity. The extent of modifications was found to be dependent on the nature of the oxo-compound used and progressed in the glucose相似文献
823.
Komitopoulou K Christophides GK Kalosaka K Chrysanthis G Theodoraki MA Savakis C Zacharopoulou A Mintzas AC 《Insect biochemistry and molecular biology》2004,34(2):149-157
This review summarizes structural and functional studies on medfly promoters and regulatory elements that can be used for driving sex-specific, conditional and constitutive gene expression in this species. Sex-specific and conditional promoters are important for generating transgenic sexing strains that could increase the performance of the Sterile Insect Technique while strong constitutive promoters are necessary for developing sensitive transgenic marker systems. The review focuses on the functional analysis of the promoters of two male-specific and heat shock medfly genes. A special emphasis is put on the potential utility of these promoters for developing transgenic sexing strains. 相似文献
824.
Population‐level assessment of genetic diversity and habitat fragmentation in critically endangered Grauer's gorillas 下载免费PDF全文
825.
826.
Cristina Castanha Biao Zhu Caitlin E. Hicks Pries Katerina Georgiou Margaret S. Torn 《Biogeochemistry》2018,137(1-2):267-279
The breakdown and decomposition of plant inputs are critical for nutrient cycling, soil development, and climate-ecosystem feedbacks, but uncertainties persist in how the rates and products of litter decomposition are affected by soil temperature, rhizosphere, and depth of input. We investigated the effects of soil warming (+ 4 °C), rhizosphere, and depth of litter placement on the decomposition of Avena fatua (wild oat grass) root litter in a Mediterranean grassland ecosystem. Field lysimeters were subjected to three environmental treatments (heating, control, and plant removal) and three 13C-labeled root litter addition treatments (to A horizon, to B horizon, and no-addition disturbance control) for each of two harvest time points. We buried root litter in February 2014 and measured loss of 13C in CO2 from the soil surface and in leachate as dissolved organic carbon (DOC) over two growing seasons. At the end of each growing season we recovered the 13C remaining in the soil. Loss of root litter C occurred almost entirely via heterotrophic respiration, with an estimated < 2% lost as DOC during the initial decay period. The added roots were broken down and incorporated into bulk soil material very quickly; only ~ 30% of added root was visible after 6 months. In the first growing season, decomposition occurred faster in the B than in the A horizon, the latter having greater moisture limitation. Subsequently, there was almost no further decomposition in the B horizon. After two growing seasons, less than 20% of the added root litter C remained in the A or B horizons of all environmental treatments. Heating did not stimulate decomposition, likely because it exacerbated the moisture limitation. However, while plots without plants dried down more slowly than plots with plants, their decomposition rate was not significantly greater, possibly due to the lack of rhizosphere processes such as priming. We conclude that in this Mediterranean grassland ecosystem, soil moisture, which is affected by season, depth, heating, and rhizosphere, plays a dominant role in mediating the effect of those factors on root litter decomposition, which after two seasons did not differ by depth or by treatment. 相似文献
827.
Katerina Apostolopoulou Dimitris Konstantinou Rodoula Alataki Ioannis Papapostolou Dimitrios Zisimopoulos Electra Kalaitzopoulou Vasiliki Bravou Ioannis Lilis Fevronia Angelatou Helen Papadaki Christos D. Georgiou Elisabeth Chroni 《Neurochemical research》2018,43(3):650-658
An ischemia/reperfusion injury of rat’s sciatic nerve was experimentally developed. In this model, we measured the in vivo production of superoxide radical, as a marker of oxidative stress and the occludin expression as an indicator of blood-nerve barrier function and we examined potential protective innervations against these abnormalities. Right sciatic nerves of the animals underwent 3 h of ischemia followed by 7 days of reperfusion and were divided into three groups: ischemic, pretreated with vitamin C in conjunction with vitamin E and treated with tissue plasminogen activator. Compared to measurements from left sciatic nerves used as sham, the ischemic group showed significantly increased superoxide radical and reduced expression of occludin in western blot and immunohistochemistry. No such differences were detected between sham and nerves in the vitamin or tissue plasminogen activator groups. It is suggested that the experimental ischemia/reperfusion model was suitable for studying the relationship between oxidative state and blood-nerve barrier. The reversion of abnormalities by the applied neuroprotective agents might prove to be a clinically important finding in view of the implication of vascular supply derangement in various neuropathies in humans. 相似文献
828.
829.
Christian Sämann Katerina Kelesiadou Seyedeh Sheida Hosseinioun Mario Wachtler Jürgen R. Köhler Kai Peter Birke Markus B. Schubert Jürgen H. Werner 《Liver Transplantation》2018,8(1)
This study presents the first laser porosificated silicon anode for lithium‐ion batteries. The pulsed laser induced pore creation improves the cycling stability of the d = 210 nm thick sputtered thin film anodes compared to plain Si. Galvanostatic cycling with a charge capacity limited to C = 932 mAh g?1 and a 2C current rate shows a stable cycling for more than N = 600 cycles. After N = 3000 cycles the laser porosificated and crystallized Si has a remaining capacity of C3000 > 120 mAh g?1. Postmortem scanning electron microscopy images after N = 3000 cycles prove that the laser porosification reduces cracks in the active layer. 相似文献
830.
It has been suggested that insectivorous birds may be guided by herbivore-induced plant volatiles (HIPVs) to herbivore-rich trees with herbivorous damage. The HIPV production in plants is partly mediated by jasmonic acid signalling pathway. Methyl jasmonate (MeJA) was proved to be a suitable agent for induction of HIPVs similar to those induced by herbivorous insects in many plant species. We studied the effects of methyl jasmonate on volatile emission and natural enemy attraction using mature grey willow (Salix cinerea) under natural conditions in Czech Republic. We treated 12 experimental shrubs with 30 mM MeJA and completed the experiment with 12 control shrubs. We monitored attacks by natural predators with artificial plasticine caterpillars which were checked daily. Birds most often pecked the caterpillars exposed on MeJA-treated shrubs and this attractiveness differed significantly from control. Attractiveness of MeJA-treated shrubs did not differ significantly from control shrubs for arthropod predators. Spraying MeJA on grey willows resulted in significantly higher production of α-pinene, β-pinene, 3-carene, limonene and β-ocimene. There was a marginally significant positive correlation between the predation rate by birds and relative change in α-pinene emissions. 相似文献