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Endocrine regulation of the reproduction in crustaceans: Identification of potential targets for toxicants and environmental contaminants 总被引:1,自引:0,他引:1
Edita Mazurová Klára Hilscherová Rita Triebskorn Heinz-R. Köhler Blahoslav Maršálek Luděk Bláha 《Biologia》2008,63(2):139-150
Progress in ecotoxicological research documents that crustaceans are highly vulnerable to diverse chemicals and toxicants
in the environment. In particular, pollutants affecting endocrine homeostasis in crustaceans (i.e., endocrine disruptors)
are intensively studied, and serious reproductive disorders have been documented. In this review, current knowledge about
the endocrine regulation of the crustacean reproduction is put together with the published ecotoxicological data with an attempt
to summarize the potential of xenobiotics to affect crustacean reproduction. Following gaps and trends were identified: (1)
Studies are required in the field of neurohormone (serotonin and dopamine) regulation of the reproduction and possible modulations
by environmental toxicants such as antidepressant drugs. (2) Molting-related parameters (regulated by ecdysteroid hormones)
are closely coordinated with the development and reproduction cycles in crustaceans (cross-links with methyl farnesoate signalling),
and their susceptibility to toxicants should be studied. (3) Other biochemical targets for xenobiotics were recently discovered
in crustaceans and these should be explored by further ecotoxicological studies (e.g., new information about ecdysteroid receptor
molecular biology). (4) Some sex steroid hormones known from vertebrates (testosterone, progesterone) have been reported in
crustaceans but knowledge about their targets (crustacean steroid receptors) and signalling is still limited. (5) Determination
of the sex in developing juveniles (affecting the sex ratio in population) is a sensitive parameter to various xenobiotics
(including endocrine disruptors) but its modulation by general environmental stress and non-specific toxicity should be further
studied. 相似文献
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Pangallo D Drahovska H Harichova J Karelova E Chovanova K Aradska J Ferianc P Turna J Timko J 《Antonie van Leeuwenhoek》2008,93(1-2):193-203
The aim of the work was the evaluation of different PCR-based methods to found an appropriate identification and typing strategy
for environmental enterococci. Environmental enterococci were isolated mainly from surface- and waste-waters. Species identification
was provided by combination of phenotypic (Micronaut System, Merlin) and molecular detection methods (fluorescent ITS-PCR,
ddl-PCR, REP-PCR, AFLP). Very similar results were observed among molecular methods, however several discrepancies were recognized
during comparison of molecular and biochemical identification. Seven enterococcal species (E. faecium, E. hirae, E. casseliflavus, E. mundtii, E. faecalis, E. durans and E. gallinarum) were identified within 166 environmental isolates. The results obtained in this work attest the importance of PCR-based
methods for identification and typing of environmental enterococci. The fluorescent ITS-PCR (fITS-PCR) showed the best results
in order to identify the enterococci strains, the method used the automated capillary electrophoresis to separate the PCR
products in a very rapid and precise way. The AFLP method was suitable to identify and characterize the isolates, while the
REP-PCR can be used for species identification. 相似文献
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Edita Tylov�� Lenka Steinbachov�� Ale? Soukup V��t Gloser Olga Votrubov�� 《Hydrobiologia》2013,700(1):141-155
Phragmites australis and Glyceria maxima are fast-growing littoral grasses often competing for similar wetland habitats. Eutrophication affects their competitiveness, but the outcome is not generally predictable due to the complexity of interrelated factors. We hypotheses that pore water N:P and NH4 +:NO3 ? modify their growth and metabolic responses to the trophic status of the habitat. The hypothesis was tested under standardized conditions of long-term sand cultures. Application of N?+?P up to extreme levels in combination with N:P?<?10 and NH4 +:NO3 ??<?1 triggered positive growth response in both species. In contrast, similar N levels applied in N:P?>?90 and NH4 +:NO3 ??=?4 caused lower productivity, changes in resource allocation, morphology and metabolic relations (e.g. high shoot density, low shoot diameters and heights, reduced root and rhizome growth). Observed signs of stress resembled the factors associated with the reed retreat at the die-back sites. Unbalanced N levels obviously alter plant susceptibility to stresses (altering, e.g. ventilation efficiency, plant anchorage or below-ground storage capacity). The positive effect of sufficient P supply was pronounced in Glyceria. It might therefore favour Glyceria in competition with Phragmites at highly fertile habitats rich in P. 相似文献
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Teaching in nature? Naturally! 总被引:1,自引:0,他引:1
Elementary school children spend less and less time outdoors in nature. In this way they will neither become familiar with plants and animals in their environment, nor will their environmental awareness develop. The solution for them would be to spend more quality time outdoors. In this work 170 teachers from Hungary and 170 teachers from Serbia shared their experiences and opinions about outdoor education. The aim was to determine whether they thought that outdoor classes were an effective method to bring pupils closer to nature. The research showed that teachers from both countries found teaching in a real environment vital but could not always implement it. They need help in the form of ideas, teaching programs and professional development courses to be confident and motivated to hold more outdoor classes. 相似文献
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Maurício da Fonseca Maria João Jurak Edita Kataja Kim Master Emma R. Berrin Jean-Guy Stals Ingeborg Desmet Tom Van Landschoot Anita Briers Yves 《Applied microbiology and biotechnology》2018,102(23):10091-10102
Applied Microbiology and Biotechnology - Carbohydrate-active enzyme discovery is often not accompanied by experimental validation, demonstrating the need for techniques to analyze substrate... 相似文献
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Gametes alter the oviductal secretory proteome 总被引:1,自引:0,他引:1
Georgiou AS Sostaric E Wong CH Snijders AP Wright PC Moore HD Fazeli A 《Molecular & cellular proteomics : MCP》2005,4(11):1785-1796
The mammalian oviduct provides an optimal environment for the maturation of gametes, fertilization, and early embryonic development. Secretory cells lining the lumen of the mammalian oviduct synthesize and secrete proteins that have been shown to interact with and influence the activities of gametes and embryos. We hypothesized that the presence of gametes in the oviduct alters the oviductal secretory proteomic profile. We used a combination of two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry to identify oviductal protein secretions that were altered in response to the presence of gametes in the oviduct. The oviductal response to spermatozoa was different from its response to oocytes as verified by Western blotting. The presence of spermatozoa or oocytes in the oviduct altered the secretion of specific proteins. Most of these proteins are known to have an influence on gamete maturation, viability, and function, and there is evidence to suggest these proteins may prepare the oviductal environment for arrival of the zygote. Our findings suggest the presence of a gamete recognition system within the oviduct capable of distinguishing between spermatozoa and oocytes. 相似文献
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O. G. Baklavadzhyan A. G. Darbinyan I. Kh. Taturyan R. V. Sarukhanyan 《Neurophysiology》1987,19(6):606-612
The comparative effectiveness of the inhibitory influence of tetanic (100 Hz) stimulation of the hypothalamus, amygdala, and limbic cortex on electromyograph (EMG) response in m. digastricus produced by electrical stimulation of tooth pulp afferents was investigated in cats anesthetized by a mixture of chloralose and Nembutal. It was found that the most pronounced inhibition of nociceptive EMG response was produced by stimulating the medial and lateral structures of the hypothalamus, a less intense response by stimulating central and medial amygdaloid nuclei, and the least reaction by stimulation of different areas of the limbic cortex. It was shown that mechanisms underlying inhibition of the jaw-opening reflex produced by hypothalamic tetanic stimulation is unconnected with the concomitant increase in blood pressure. The inhibitory action of hypothalamic tetanic stimulation following blood pressure stabilization persists; this would suggest a primary but not baroafferent mechanism underlying inhibition of activity in trigeminal nucleus nociceptive neurons. Pronounced and protracted depression of jaw-opening reflex takes place following long-term pressor response produced by injecting noradrenaline intravenously. The same pronounced and protracted pressor response occurs under the effects of angiotensin but without any noticeable change in the amplitude of nociceptive EMG response. Hypothalamic and noradrenergic mechanisms of pain sensitivity are discussed.L. A. Orbeli Institute of Physiology, Academy of Sciences of the Armenian SSR, Erevan. Translated from Neirofiziologiya, Vol. 19, No. 6, pp. 825–832, November–December, 1987. 相似文献