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81.
Dispersal Potential is Affected by Growth-Hormone Transgenesis in Coho Salmon (Oncorhynchus kisutch)
L. Fredrik Sundström Mare Lõhmus Jörgen I. Johnsson† & Robert H. Devlin 《Ethology : formerly Zeitschrift fur Tierpsychologie》2007,113(4):403-410
Potential ecological consequences on the natural environment of fast‐growing transgenic fish with elevated intrinsic growth rates is an important question should such fish be allowed in commercial production systems. One trait that will strongly affect the spatial extent of consequences is the propensity of transgenic fish to disperse. We addressed this question in three experiments using different measures of spatial dispersal where we compared very young genotypically wild coho salmon with transgenic conspecifics in terms of: (i) group cohesion, (ii) exploratory behavior, and (iii) up‐ and downstream movements. Transgenic fish were more loosely aggregated, more likely to explore, and less likely to swim upstream, but equally likely to disperse downstream compared with genetically wild fish. These results show that dispersal behavior has been affected by transgenesis and that transgenic fish therefore may venture into habitats previously not used by wild fish. Given the importance of dispersal in ecological risk‐assessment of transgenic fish, continued work within this area is warranted and experimental habitats should mimic the potential receiving natural habitats to which transgenic fish are likely to escape or be released to. 相似文献
82.
Mareš P Bernášková K Kubová H 《Physiological research / Academia Scientiarum Bohemoslovaca》2012,61(3):325-329
Cortical epileptic foci elicited by local application of bicuculline methiodide represent a model of interictal epileptic activity with a transition into ictal phases. We studied a role of GABA-B receptors in this model using GABA-B receptor antagonist CGP35348 in adult rats with implanted cortical electrodes and cannula. CGP35348 (100 or 200 mg/kg i.p.) did not affect interictal discharges but it augmented ictal activity. Latency to the first ictal episode was decreased by the lower dose of CGP35348, duration of episodes was increased by the higher dose. GABA-B receptor antagonist did not influence purely cortical epileptic phenomenon but it is proconvulsant in ictal activity generated with participation of subcortical structures. 相似文献
83.
We report the first case of tinea corporis bullosa due to Trichophyton schoenleinii in a 41-year-old Romanian woman, without any involvement of the scalp and hair. The species identification was performed using macroscopic and microscopic features of the dermatophyte and its physiological abilities. Epidemiological aspects of the case are also discussed. The general treatment with terbinafine and topical applications of ciclopiroxolamine cream have led to complete healing, with the lesions disappearing in 2?weeks. 相似文献
84.
Mareš V Stremeňová J Lisá V Kozáková H Marek J Syrůček M Šoula O Šedo A 《Histology and histopathology》2012,27(7):931-940
γ-Glutamyltranspeptidase (GGT, syn. γ-Glutamyltransferase) and dipeptidylpeptidase-IV (DPP-IV) activity participates in metabolic and growth control of normal and tumor cells by processing biologically active peptides. Here, we report on up-regulation of these enzymes in human brain gliomas determined by catalytic enzyme histochemistry and immunocytochemistry. Higher activity of GGT was found in 50%, 68% and 81% of WHO grade II, III and IV tumors, respectively. The process started at/near the microvasculature, from where it spread to the parenchyma. On average, the enzyme activity in grade II, III and IV gliomas exceeded controls 2.0, 3.0 and 3.5-fold, respectively. Up-regulation of DPP-IV-like activity also started at the microvasculature, but mainly in pericytes and mononuclear-like cells around the vessels and dispersed in the parenchyma. Marked elevation of this enzyme activity, comprising also tumor parenchyma, occurred only in grade IV glioblastomas (65% patients; 3.6 times above controls) which can, therefore, help in their differentiation from grade III gliomas. The increase of total DPP-IV-like activity also included its two enzymatic homologs, the canonical DPP-IV/CD26 and FAP-1α. The increase in GGT is supposed to be a tumor grade dependent response of microvasculature and tumor astrocytes to stress induced by tissue hypoxia and/or the metabolic aberrancies. The increase in DPP-IV-like activity in high-grade tumors can be attributed to inflammatory/scavenging processes performed by the mononuclear-like cells and, in glioblastomas, also to regressive changes in the structure and function of the microvasculature and tumor parenchyma, including astrocyte stress response. The inverse relationship between DPP-IV-like activity and Ki67 in most glioblastomas and shorter survival time of patients with low activity of this enzyme also suggest its anti-oncogenic effects. 相似文献
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87.
Hydroxylysine (Hyl) is a posttranslationally modified amino acid found mainly in collagens, the most abundant protein in mammals. Lysyl hydroxylase (LH) catalyzes the hydroxylation of the C-5 position of a Lys residue, resulting in the production of Hyl. Mechanistically, LH incorporates one oxygen atom into both Lys and 2-oxoglutarate; the latter is decarboxylated to form succinate and CO(2). To develop a convenient, RP-HPLC based LH assay, we used Fmoc solid-phase methodology to synthesize three different peptides designed as LH substrates and one peptide corresponding to an LH product. Peptides were characterized by RP-HPLC, MALDI-TOF mass spectrometry and CD spectroscopy. Separation of peptides was examined under a variety of RP-HPLC conditions. The best results were achieved using peptide derivatization (1-anthroylnitrile for organic phase and dansyl chloride for aqueous phase) prior to RP-HPLC analysis. The products (di- and tetra-substituted Lys- and Hyl-containing peptides) were well resolved by RP-HPLC. The resolution of each peak allows for quantification of peak areas, which in turn, when examined as a function of time, can be utilized for studying the kinetics of LH catalyzed reactions. Most significantly, the RP-HPLC assay directly monitors the Hyl containing product. Prior LH assay methods are multi-step, require radio-labeled substrates, and/or measure depletion of 2-oxoglutarate or formation of CO(2). Since the LH reaction with 2-oxoglutarate is uncoupled from Lys hydroxylation, the most accurate assay of LH activity should monitor the formation of Hyl. 相似文献
88.
Petr?SmykalEmail author Michala?Chaloupská Michael?Bariotakis Lucie?Mare?ková Andrey?Sinjushin Ivan?Gabrielyan Janna?Akopian Cengiz?Toker Gregory?Kenicer Miloslav?Kitner Stergios?Pirintsos 《Plant Systematics and Evolution》2017,303(3):267-282
Vavilovia formosa is one of five genera in tribe Fabeae, (Fabaceae, Leguminosae) with close phylogenetic relationships to Pisum. It grows in subalpine and alpine levels in Armenia, Azerbaijan, Georgia, Iran, Iraq, Lebanon, Russia and Turkey and is recognized as an endangered and protected plant. This study was conducted to reveal its intraspecific variability, as well as to predict the past, extant and future species distribution range. We analysed 51 accessions with common phylogenetic markers (trnF-trnL, trnS-trnG, matK, rbcL, psbA-trnH and ITS). These represent in total up to 2551 bp of chloroplast and 664 bp of nuclear sequences per sample. Two populations from Turkey and Armenia were analysed for genetic diversity by AFLP. Leaf morphometry was conducted on 1457 leaflets from 43 specimens. Extracted bioclimatic parameters were used for niche-modelling approach. Analysis of cpDNA revealed two haplotypes, 12 samples from Armenia, Daghestan, Nakhichevan and Iran belonged to H1 group, while 39 samples of all Turkish and part of Armenian were in H2 group. The mean intrapopulation diversity based on AFLP was low (H E = 0.088) indicating limited outcrossing rate. A significantly positive correlation between geographical latitude and leaf area (\(\rho\) = 0.527, p < 0.05) was found. Niche modelling has shown temporal variation of predicted occurrence across the projected time periods. Vavilovia formosa has suffered a range reduction following climate warming after last glacial maximum, which classify this species as cold-adapted among the Fabeae species as well as a glacial relict. 相似文献
89.
Cyanomargarita gen. nov. (Nostocales,Cyanobacteria): convergent evolution resulting in a cryptic genus
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Sergei Shalygin Regina Shalygina Jeffrey R. Johansen Nicole Pietrasiak Esther Berrendero Gómez Markéta Bohunická Jan Mareš Christopher A. Sheil 《Journal of phycology》2017,53(4):762-777
Two populations of Rivularia‐like cyanobacteria were isolated from ecologically distinct and biogeographically distant sites. One population was from an unpolluted stream in the Kola Peninsula of Russia, whereas the other was from a wet wall in the Grand Staircase‐Escalante National Monument, a desert park‐land in Utah. Though both were virtually indistinguishable from Rivularia in field and cultured material, they were both phylogenetically distant from Rivularia and the Rivulariaceae based on both 16S rRNA and rbcLX phylogenies. We here name the new cryptic genus Cyanomargarita gen. nov., with type species C. melechinii sp. nov., and additional species C. calcarea sp. nov. We also name a new family for these taxa, the Cyanomargaritaceae. 相似文献
90.
There exist differences between 12-day-old and adult rats in the onset of seizures induced by some inhibitors of glutamate decarboxylase (GAD). The aim of study was to investigate if there are differences between both groups in activities of rat brain alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the enzymes involved in glutamate metabolism, after the administration of 3-mercaptopropionic acid as specific GAD inhibitor or isoniazid as less specific general inhibitor of pyridoxal enzymes. Activities of both aminotransferases in a supernatant 20,000 g of the whole brain (containing predominantly cytosolic isoforms of enzymes) were increased at the beginning of 3-mercaptopropionic acid-induced generalized tonic-clonic seizures. At isoniazid-induced generalized tonic-clonic seizures, a significant increase in both enzyme activities was observed in adult rat brain. In the 12-day-old rat brain, ALT and AST activities reached about 40% and about 50–60% of adult control levels, respectively. In in vitro experiments, no influence of 3-mercaptopropionic acid on transaminase activities was found and an inhibitory effect of isoniazid on the enzymes was confirmed. Increased aminotransferase activities might participate in the enhanced synthesis of excitatory amino acid neurotransmitters in the nervous system, which may take a part in the initiation of epileptic seizures. Alternatively, the increased AST activity may be connected with an increased transport of NADH from the cytosol to mitochondria, while the increased ALT activity would represent the transformation of pyruvate to alanine as a consequence of increased glycolysis. 相似文献