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81.
Vance W. Berger YanYan Zhou Anastasia Ivanova Lothar Tremmel 《Biometrical journal. Biometrische Zeitschrift》2004,46(1):48-55
In the context of randomized clinical trials, multiplicity arises in many forms. One prominent example is when a key endpoint is measured and analyzed both at baseline and after treatment. It is common to analyze each separately, but more efficient to adjust the post‐treatment comparisons for the baseline values. Adjustment techniques generally treat the covariate (baseline value, in this case) as either nominal or continuous. Either is problematic when applied to an ordinal covariate, the former because it fails to exploit the natural ordering and the latter because it relies on an artifical notion of linear prediction and differences between values. We propose new methods for adjusting for ordinal covariates without having to treat them as nominal or continuous. Specifically, the information‐preserving composite endpoint consists of the pair of values for each patient, one at baseline and one after treatment. Some of these patterns will indicate more improvement than others, yet some pairs of patterns are not comparable. Hence, the ordering is only partial. We develop an approach to testing and deriving estimators of magnitudes of the treatment effect based on comparing each observation in one group to each observation in the other group to which it is comparable. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Anastasia Chasapi Paulina Wachowicz Anne Niknejad Philippe Collin Andrea Krapp Elena Cano Viesturs Simanis Ioannis Xenarios 《PloS one》2015,10(8)
Cytokinesis in fission yeast is controlled by the Septation Initiation Network (SIN), a protein kinase signaling network using the spindle pole body as scaffold. In order to describe the qualitative behavior of the system and predict unknown mutant behaviors we decided to adopt a Boolean modeling approach. In this paper, we report the construction of an extended, Boolean model of the SIN, comprising most SIN components and regulators as individual, experimentally testable nodes. The model uses CDK activity levels as control nodes for the simulation of SIN related events in different stages of the cell cycle. The model was optimized using single knock-out experiments of known phenotypic effect as a training set, and was able to correctly predict a double knock-out test set. Moreover, the model has made in silico predictions that have been validated in vivo, providing new insights into the regulation and hierarchical organization of the SIN. 相似文献
85.
Michael T. Bowen Shantala A. Hari Dass Jessica Booth Anastasia Suraev Ajai Vyas Iain S. McGregor 《Hormones and behavior》2014
An active coping style displayed under stress – which involves proactive investigatory responses toward environmental threats – has been associated with reduced vulnerability to psychiatric illness. However, the neurobiological determinants of coping styles are not well understood. When rats are exposed to a naturalistic stressor (cat fur) in a group, some individuals in the group show robust active investigation of the stimulus while others show a passive response involving retreat, immobility and close aggregation with conspecifics. Here we explored endocrine and epigenetic correlates of these contrasting coping styles. Male Wistar rats (n = 48) were exposed to cat fur in groups of 4 and the passive and active responders were identified and assessed for endocrine and epigenetic differences. Three days after the final cat fur exposure, active responders had substantially lower plasma levels of corticosterone and progesterone than passive responders. Plasma and testicular testosterone levels did not differ between active and passive responders. Active responders had markedly less methylation of the AVP CGCG promoter region located at base 4970 in the posterodorsal region of the medial amygdala but did not differ in the methylation status of the CCGG sequence located at base 2243. This is in agreement with prior research suggesting that AVP and progesterone act in opposition within the medial amygdala to modulate stress-related behaviors. The present study reports striking endocrine and epigenetic differences between active and passive responders, providing insight into potential systems involved in the manifestation of differing coping styles. 相似文献
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Marina Roussaki Christos A. Kontogiorgis Dimitra Hadjipavlou-Litina Stylianos Hamilakis Anastasia Detsi 《Bioorganic & medicinal chemistry letters》2010,20(13):3889-3892
A series of coumarin analogues bearing a substituted phenyl ring on position 3 were synthesized via a novel methodology, through an intermolecular condensation reaction of 2-hydroxyacetophenones and 2-hydroxybenzaldehyde, with imidazolyl phenylacetic acid active intermediates. The in vitro antioxidant activity of the synthesized compounds was evaluated using two different antioxidant assays (radical scavenging ability of DPPH stable free radical and inhibition of lipid peroxidation induced by the thermal free radical AAPH). Moreover, the ability of the compounds to inhibit soybean lipoxygenase was determined as an indication of potential anti-inflammatory activity. 相似文献
88.
Demetrios Tzimopoulos Anastasia.-C. Varvogli Maria Gdaniec Eleni Nikolakaki Pericles D. Akrivos 《Journal of inorganic biochemistry》2010,104(4):423-8167
The synthesis and study of trimethyl-, tributyl- and triphenyltin esters of the 3- and 4-aminobenzoic acids are reported. The triorganotin derivatives are characterized by elemental analyses, FT-IR and solution 1H and 13C NMR spectra. The structure of the trimethyltin 4-aminobenzoate is solved by X-ray diffraction and proves to be polymeric in nature with bridging carboxylates and trigonal bipyramidal tin(IV) environment. However, all the compounds become monomeric in solution with a tetrahedral tin coordination environment in chloroform and trigonal bipyramidal in DMSO due to coordination of the solvent as the NMR spectra have revealed. The compounds exhibit variable cytotoxic activity when tested against Κ562 myelogenous leukaemia, HeLa cervical cancer and HepG2 hepatocellular carcinoma cell lines, with the butyl derivatives being the more effective and the methyl ones the less. Interestingly, their antibacterial action was significantly lower when tested against Escherichia coli, while not appreciable direct interaction with DNA has been observed. The above observations account for a mode of action that may be related to their potential interaction with cell membranes and the subsequent inhibition of various signaling processes. 相似文献
89.
Nina Desai Anastasia Alex Faten AbdelHafez Anthony Calabro James Goldfarb Aaron Fleischman Tommaso Falcone 《Reproductive biology and endocrinology : RB&E》2010,8(1):119
In vitro ovarian follicle culture is a new frontier in assisted reproductive technology with tremendous potential, especially
for fertility preservation. Folliculogenesis within the ovary is a complex process requiring interaction between somatic cell
components and the oocyte. Conventional two-dimensional culture on tissue culture substrata impedes spherical growth and preservation
of the spatial arrangements between oocyte and surrounding granulosa cells. Granulosa cell attachment and migration can leave
the oocyte naked and unable to complete the maturation process. Recognition of the importance of spatial arrangements between
cells has spurred research in to three-dimensional culture system. Such systems may be vital when dealing with human primordial
follicles that may require as long as three months in culture. In the present work we review pertinent aspects of in vitro
follicle maturation, with an emphasis on tissue-engineering solutions for maintaining the follicular unit during the culture
interval. We focus primarily on presenting the various 3-dimensional culture systems that have been applied for in vitro maturation
of follicle:oocyte complexes. We also try to present an overview of outcomes with various biomaterials and animal models and
also the limitations of the existing systems. 相似文献
90.
Akunevich Anastasia Aleksandrovna Khrustalev Vladislav Victorovich Khrustaleva Tatyana Aleksandrovna Poboinev Victor Vitoldovich Shalygo Nikolai Vladimirovich Stojarov Aleksander Nicolaevich Arutyunyan Alexander Migranovich Kordyukova Larisa Valentinovna Sapon Yehor Gennadyevich 《The protein journal》2022,41(2):245-259
The Protein Journal - An interplay between monomeric and dimeric forms of human epidermal growth factor (EGF) affecting its interaction with EGF receptor (EGFR) is poorly understood. While EGF... 相似文献