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991.
O Bangcharoenpaurpong A K Rizos P M Champion D Jollie S G Sligar 《The Journal of biological chemistry》1986,261(18):8089-8092
We have used resonance Raman spectroscopy and isotopic labeling techniques to unambiguously assign the dioxygen stretching frequency (vo-o) in the substrate-bound oxygenated complex of cytochrome P-450cam. The frequency found for Vo-o in the P-450cam system (1140 cm-1) is in remarkable agreement with recent studies of thiolate heme model compounds. The general features of the oxy-P-450cam Raman spectra are tabulated and comparisons are made with the oxy complexes of hemoglobin, myoglobin, and various model compounds. Most of the results are qualitatively explained by consideration of electron donation into the pi g (O2)/d pi (M) orbitals of the oxygenated complex (M = Fe or Co). It is also noted that the effect of the "extra" electron in the nitrogen base Co(II) oxy complexes, in some ways, parallels the effect of the lone pair electrons of thiolate in the oxy-P-450cam complex. This is evidenced by the enhanced resonance Raman activity of vo-o in both the Co(II) and P-450 systems as well as by the similarity of the vo-o frequencies. 相似文献
992.
Heleen Demeyer Elena Gimeno-Santos Roberto A. Rabinovich Miek Hornikx Zafeiris Louvaris Willem I. de Boer Niklas Karlsson Corina de Jong Thys Van der Molen Ioannis Vogiatzis Wim Janssens Judith Garcia-Aymerich Thierry Troosters Michael I. Polkey PROactive consortium 《PloS one》2016,11(3)
Background
The GOLD multidimensional classification of COPD severity combines the exacerbation risk with the symptom experience, for which 3 different questionnaires are permitted. This study investigated differences in physical activity (PA) in the different GOLD quadrants and patient’s distribution in relation to the questionnaire used.Methods
136 COPD patients (58±21% FEV1 predicted, 34F/102M) completed COPD assessment test (CAT), clinical COPD questionnaire (CCQ) and modified Medical Research Council (mMRC) questionnaire. Exacerbation history, spirometry and 6MWD were collected. PA was objectively measured for 2 periods of 1 week, 6 months apart, in 5 European centres; to minimise seasonal and clinical variation the average of these two periods was used for analysis.Results
GOLD quadrants C+D had reduced PA compared with A+B (3824 [2976] vs. 5508 [4671] steps.d-1, p<0.0001). The choice of questionnaire yielded different patient distributions (agreement mMRC-CAT κ = 0.57; CCQ-mMRC κ = 0.71; CCQ-CAT κ = 0.72) with different clinical characteristics. PA was notably lower in patients with an mMRC score ≥2 (3430 [2537] vs. 5443 [3776] steps.d-1, p <0.001) in both the low and high risk quadrants.Conclusions
Using different questionnaires changes the patient distribution and results in different clinical characteristics. Therefore, standardization of the questionnaire used for classification is critical to allow comparison of different studies using this as an entry criterion.Clinical Trial Registration
ClinicalTrials.gov NCT01388218相似文献993.
Ricaurte Lopera-Vásquez Meriem Hamdi Beatriz Fernandez-Fuertes Verónica Maillo Paula Beltrán-Bre?a Alexandra Calle Alberto Redruello Soraya López-Martín Alfonso Gutierrez-Adán María Ya?ez-Mó Miguel ángel Ramirez Dimitrios Rizos 《PloS one》2016,11(2)
To evaluate the effect of conditioned media (CM) and Extracellular Vesicles (EVs) derived from bovine oviduct epithelial cell (BOEC) lines on the developmental capacity of bovine zygotes and the quality of embryos produced in vitro, presumptive zygotes were cultured under specific conditions. In experiment 1, zygotes were cultured either on monolayers from BOEC extended culture (E), together with fresh BOEC suspension cells, or with BOEC-CM from fresh or E-monolayers. In experiment 2, EVs were isolated from BOEC-CM and characterized (150–200 nm) by Nanosight® and electron microscopy. Zygotes were cultured in the presence of 3x105EVs/mL, 1.5x105EVs/mL or 7.5x104EVs/mL of fresh or frozen BOEC-EVs. In experiment 3, zygotes were cultured in absence of FCS but with EVs from BOEC-E that had been cultured in different culture media. In experiment 4, zygotes were cultured in SOF+5% normal-FCS, or EV-depleted-FCS. In all cases, cleavage rate (Day 2) and blastocyst development (Day 7–9) was assessed. Blastocysts on Days 7/8 were used for quality evaluation through differential cell count, cryotolerance and gene expression patterns. No differences were found among all FCS-containing groups in cleavage rate or blastocyst yield. However, embryos derived from BOEC-CM had more trophectoderm cells, while embryos derived from BOEC-EVs, both fresh and frozen, has more trophectoderm and total cells. More embryos survived vitrification in the BOEC-CM and BOEC-EV groups. In contrast, more embryos survived in the EV-depleted-FCS than in normal-FCS group. Gene expression patterns were modified for PAG1 for embryos cultured with EVs in the presence of FCS and for IFN-T, PLAC8, PAG1, CX43, and GAPDH in the absence of FCS. In conclusion, EVs from FCS have a deleterious effect on embryo quality. BOEC-CM and EVs during in vitro culture had a positive effect on the quality of in vitro produced bovine embryos, suggesting that EVs have functional communication between the oviduct and the embryo in the early stages of development. 相似文献
994.
Zoe Hilioti Ioannis Ganopoulos Sabna Ajith Ioannis Bossis Athanasios Tsaftaris 《Plant cell reports》2016,35(11):2241-2255
Key message
A selection-free, highly efficient targeted mutagenesis approach based on a novel ZFN monomer arrangement for genome engineering in tomato reveals plant trait modifications.Abstract
How to achieve precise gene targeting in plants and especially in crops remains a long-sought goal for elucidating gene function and advancing molecular breeding. To address this issue, zinc finger nuclease (ZFN)-based technology was developed for the Solanum lycopersicum seed system. A ZFN architecture design with an intronic sequence between the two DNA recognition sites was evaluated for its efficiency in targeted gene mutagenesis. Custom engineered ZFNs for the developmental regulator LEAFY-COTYLEDON1-LIKE4 (L1L4) coding for the β subunit of nuclear factor Y, when transiently expressed in tomato seeds, cleaved the target site and stimulated imperfect repair driven by nonhomologous end-joining, thus, introducing mutations into the endogenous target site. The successful in planta application of the ZFN platform resulted in L1L4 mutations which conferred heterochronic phenotypes during development. Our results revealed that sequence changes upstream of the DNA binding domain of L1L4 can lead to phenotypic diversity including fruit organ. These results underscore the utility of engineered ZFN approach in targeted mutagenesis of tomato plant which may accelerate translational research and tomato breeding.995.
Dimitris P. Makris Vassiliki Passalidi Stamatina Kallithraka Ioannis Mourtzinos 《Preparative biochemistry & biotechnology》2016,46(2):176-182
Grape pomace is a food industry waste containing a high burden of antioxidant polyphenols and several methodologies have been developed for their efficient extraction. However, a sustainable and environmentally friendly process should involve recovery means composed of benign, non-toxic solvents, such as tartaric acid and glycerol, which are natural food constituents. In this line, this study examined the extraction of polyphenols using aqueous tartaric acid/glycerol solutions. The aim was to assess the role of acid and glycerol concentration in the extraction yield, employing a Box-Behnken experimental design and response surface methodology. The results showed that solutions containing only glycerol (20%, w/v) are more suitable for retrieving polyphenols, flavonoids, and pigments from grape pomace, while tartaric acid exerted a negative effect in this regard, when tested at concentrations up to 2% (w/v). 相似文献
996.
Rob J. De Boer Alan S. Perelson Ioannis G. Kevrekidis 《Bulletin of mathematical biology》1993,55(4):745-780
We develop a model for the idiotypic interaction between two B cell clones. This model takes into account B cell proliferation,
B cell maturation, antibody production, the formation and subsequent elimination of antibody-antibody complexes and recirculation
of antibodies between the spleen and the blood. Here we investigate, by means of stability and bifurcation analysis, how each
of the processes influences the model's behavior. After appropriate nondimensinalization, the model consists of eight ordinary
differential equations and a number of parameters. We estimate the parameters from experimental sources. Using a coordinate
system that exploits the pairwise symmetry of the interactions between two clones, we analyse two simplified forms of the
model and obtain bifurcation diagrams showing how their five equilibrium states are related. We show that the so-called immune
states lose stability if B cell and antibody concentrations change on different time scales. Additionally, we derive the structure
of stable and unstable manifolds of saddle-tye equilibria, pinpoint their (global) bifurcations and show that these bifurcations
play a crucial role in determining the parameter regimes in which the model exhibits oscillatory behavior. 相似文献
997.
Fabienne Billiard Sevasti Karaliota Bei Wang Dimitrios Stellas Ioannis Serafimidis Antigoni Manousopoulou Yiassemi Koutmani Elpiniki Ninou Jacquelynn Golubov Amanda DaNave Panagiotis Tsakanikas Yurong Xin Wen Zhang Matthew Sleeman George D. Yancopoulos Andrew J. Murphy Spiros D. Garbis Katia Karalis Dimitris Skokos 《Cell reports》2018,22(4):895-904
998.
Serge Pieters David McGowan Florence Herschke Frederik Pauwels Bart Stoops Stefaan Last Werner Embrechts Annick Scholliers Wendy Mostmans Kris Van Dijck Bertrand Van Schoubroeck Tine Thoné Dorien De Pooter Gregory Fanning Mari Luz Rosauro Mourad Daoubi Khamlichi Ioannis Houpis Eric Arnoult Pierre Raboisson 《Bioorganic & medicinal chemistry letters》2018,28(4):711-719
The discovery of a novel series of highly potent quinazoline TLR 7/8 agonists is described. The synthesis and structure–activity relationship is presented. Structural requirements and optimization of this series toward TLR 7 selectivity afforded the potent agonist 48. Pharmacokinetic and pharmacodynamic studies highlighted 48 as an orally available endogenous interferon (IFN-α) inducer in mice. 相似文献
999.
Truncation of a P1 leader proteinase facilitates potyvirus replication in a non‐permissive host 下载免费PDF全文
Hongying Shan Fabio Pasin Ioannis E. Tzanetakis Carmen Simón‐Mateo Juan Antonio García Bernardo Rodamilans 《Molecular Plant Pathology》2018,19(6):1504-1510
The Potyviridae family is a major group of plant viruses that includes c. 200 species, most of which have narrow host ranges. The potyvirid P1 leader proteinase self‐cleaves from the remainder of the viral polyprotein and shows large sequence variability linked to host adaptation. P1 proteins can be classified as Type A or Type B on the basis, amongst other things, of their dependence or not on a host factor to develop their protease activity. In this work, we studied Type A proteases from the Potyviridae family, characterizing their host factor requirements. Our in vitro cleavage analyses of potyvirid P1 proteases showed that the N‐terminal domain is relevant for host factor interaction and suggested that the C‐terminal domain is also involved. In the absence of plant factors, the N‐terminal end of Plum pox virus P1 antagonizes protease self‐processing. We performed extended deletion mutagenesis analysis to define the N‐terminal antagonistic domain of P1. In viral infections, removal of the P1 protease antagonistic domain led to a gain‐of‐function phenotype, strongly increasing local infection in a non‐permissive host. Altogether, our results shed new insights into the adaptation and evolution of potyvirids. 相似文献
1000.
Alexandra V. Chatzikonstantinou Maria V. Chatziathanasiadou Enrico Ravera Marco Fragai Giacomo Parigi Ioannis P. Gerothanassis Claudio Luchinat Haralambos Stamatis Andreas G. Tzakos 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(1):1-8