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161.
162.
Oresmaa L Kotikoski H Haukka M Oksala O Pohjala E Vapaatalo H Vainiotalo P Aulaskari P 《Bioorganic & medicinal chemistry letters》2006,16(8):2144-2147
Esters of 1-(H)-imidazole-5-nitrolic acid and 1-methyl-imidazole-5-carboxamide oxime were prepared to study the effect of esterification on the ocular effects of these compounds. Esterifications were performed with acid chloride. Acid chloride also reacts with the ring nitrogen of 1-(H)-imidazole-5-nitrolic acid, but the desired esters could be selectively prepared by adjustment of the reaction conditions. Esterification led to loss of the ocular effects exhibited by the parent compounds. 相似文献
163.
Konstandi M Kostakis D Harkitis P Johnson EO Marselos M Adamidis K Lang MA 《Life sciences》2006,79(4):331-341
CYP1A2, a principal catalyst for metabolism of various therapeutic drugs and carcinogens, among others, is in part regulated by the stress response. This study was designed to assess whether catecholamines and in particular adrenergic receptor-dependent pathways, modulate benzo(alpha)pyrene (B(alpha)P)-induced hepatic CYP1A2. To distinguish between the role of central and peripheral catecholamines in the regulation of CYP1A2 induction, the effect of central and peripheral catecholamine depletion using reserpine was compared to that of peripheral catecholamine depletion using guanethidine. The effects of peripheral adrenaline and L-DOPA administration were also assessed. The results suggest that alterations in central catecholamines modulate 7-methoxyresorufin O-demethylase activity (MROD), CYP1A2 mRNA and protein levels in the B(alpha)P-induced state. In particular, central catecholamine depletion, dexmedetomidine-induced inhibition of noradrenaline release and blockade of alpha(1)-adrenoceptors with prazosin, up-regulated CYP1A2 expression. Phenylephrine and dexmedetomidine-induced up-regulation may be mediated, in part, via peripheral alpha(1)- and alpha(2)-adrenoceptors, respectively. On the other hand, the L-DOPA-induced increase in central dopaminergic activity was not followed by any change in the up-regulation of CYP1A2 expression by B(alpha)P. Central noradrenergic systems appeared to counteract up-regulating factors, most likely via alpha(1)- and alpha(2)-adrenoceptors. In contrast, peripheral alpha- and beta-adrenoceptor-related signaling pathways are linked to up-regulating processes. The findings suggest that drugs that bind to adrenoceptors or affect central noradrenergic neurotransmission, as well as factors that challenge the adrenoceptor-linked signaling pathways may deregulate CYP1A2 induction. This, in turn, may result in drug-therapy and drug-toxicity complications. 相似文献
164.
Tolvanen KE Mangayil RK Karp MT Santala VP 《Applied and environmental microbiology》2011,77(12):4246-4248
This study presents a simple enrichment system where gas pressure produced by microbes performs functions that are normally done by labor. The system was tested with Escherichia coli strains with different hydrogen production and growth capabilities. The results show that the system can enrich the best hydrogen producer. 相似文献
165.
166.
In hypersaline environments bacteria are exposed to a high osmotic pressure caused by the surrounding high salt concentrations. Halophilic microorganisms have specific strategies for balancing the osmotic pressure and surviving in these extreme conditions. Halophilic fermentative bacteria form taxonomically and phylogenetically a coherent group mainly belonging to the order Halanaerobiales. In this review, halophilic anaerobic fermentative bacteria in terms of taxonomy and phylogeny, special characteristics, survival strategies, and potential for biotechnological applications in a wide variety of branches, such as production of hydrogen, are discussed. 相似文献
167.
168.
Irina Ignatova Andrew S. French Esa-Ville Immonen Roman Frolov Matti Weckström 《Biological cybernetics》2014,108(3):305-320
Shannon’s seminal approach to estimating information capacity is widely used to quantify information processing by biological systems. However, the Shannon information theory, which is based on power spectrum estimation, necessarily contains two sources of error: time delay bias error and random error. These errors are particularly important for systems with relatively large time delay values and for responses of limited duration, as is often the case in experimental work. The window function type and size chosen, as well as the values of inherent delays cause changes in both the delay bias and random errors, with possibly strong effect on the estimates of system properties. Here, we investigated the properties of these errors using white-noise simulations and analysis of experimental photoreceptor responses to naturalistic and white-noise light contrasts. Photoreceptors were used from several insect species, each characterized by different visual performance, behavior, and ecology. We show that the effect of random error on the spectral estimates of photoreceptor performance (gain, coherence, signal-to-noise ratio, Shannon information rate) is opposite to that of the time delay bias error: the former overestimates information rate, while the latter underestimates it. We propose a new algorithm for reducing the impact of time delay bias error and random error, based on discovering, and then using that size of window, at which the absolute values of these errors are equal and opposite, thus cancelling each other, allowing minimally biased measurement of neural coding. 相似文献
169.
Matti Viluksela P?ivi Heikkinen Leo T. M. van der Ven Filip Rendel Robert Roos Javier Esteban Merja Korkalainen Sanna Lensu Hanna M. Miettinen Kari Savolainen Satu Sankari Hellmuth Lilienthal Annika Adamsson Jorma Toppari Maria Herlin Mikko Finnil? Juha Tuukkanen Heather A. Leslie Timo Hamers Gerd Hamscher Lauy Al-Anati Ulla Stenius Kine-Susann Dervola Inger-Lise Bogen Frode Fonnum Patrik L. Andersson Dieter Schrenk Krister Halldin Helen H?kansson 《PloS one》2014,9(8)
PCB 180 is a persistent non-dioxin-like polychlorinated biphenyl (NDL-PCB) abundantly present in food and the environment. Risk characterization of NDL-PCBs is confounded by the presence of highly potent dioxin-like impurities. We used ultrapure PCB 180 to characterize its toxicity profile in a 28-day repeat dose toxicity study in young adult rats extended to cover endocrine and behavioral effects. Using a loading dose/maintenance dose regimen, groups of 5 males and 5 females were given total doses of 0, 3, 10, 30, 100, 300, 1000 or 1700 mg PCB 180/kg body weight by gavage. Dose-responses were analyzed using benchmark dose modeling based on dose and adipose tissue PCB concentrations. Body weight gain was retarded at 1700 mg/kg during loading dosing, but recovered thereafter. The most sensitive endpoint of toxicity that was used for risk characterization was altered open field behavior in females; i.e. increased activity and distance moved in the inner zone of an open field suggesting altered emotional responses to unfamiliar environment and impaired behavioral inhibition. Other dose-dependent changes included decreased serum thyroid hormones with associated histopathological changes, altered tissue retinoid levels, decreased hematocrit and hemoglobin, decreased follicle stimulating hormone and luteinizing hormone levels in males and increased expression of DNA damage markers in liver of females. Dose-dependent hypertrophy of zona fasciculata cells was observed in adrenals suggesting activation of cortex. There were gender differences in sensitivity and toxicity profiles were partly different in males and females. PCB 180 adipose tissue concentrations were clearly above the general human population levels, but close to the levels in highly exposed populations. The results demonstrate a distinct toxicological profile of PCB 180 with lack of dioxin-like properties required for assignment of WHO toxic equivalency factor. However, PCB 180 shares several toxicological targets with dioxin-like compounds emphasizing the potential for interactions. 相似文献
170.
Heidi Hintsala Tuomas V. Kentt? Mikko Tulppo Antti Kiviniemi Heikki V. Huikuri Matti M?ntysaari Sirkka Kein?nen-Kiukaannemi Risto Bloigu Karl-Heinz Herzig Riitta Antikainen Hannu Rintam?ki Jouni J. K. Jaakkola Tiina M. Ik?heimo 《PloS one》2014,9(7)