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71.
Zi-Feng Jiang Fangfang Xia Kipp W. Johnson Elizabeth Bartom Jigyasa H. Tuteja Rick Stevens Robert L. Grossman Marina Brumin Kevin P. White Murad Ghanim 《Journal of bacteriology》2012,194(23):6678-6679
“Candidatus Portiera aleyrodidarum” is the obligate primary endosymbiotic bacterium of whiteflies, including the sweet potato whitefly Bemisia tabaci, and provides essential nutrients to its host. Here we report two complete genome sequences of this bacterium from the B and Q biotypes of B. tabaci. 相似文献
72.
Hao J Chen B Yao Y Hossain M Nagatomo T Yao H Kong L Sun H 《Bioorganic & medicinal chemistry letters》2012,22(10):3441-3444
Naftidrofuryl oxalate (Praxilene®, 1) has been used for the treatment of intermittent claudication for more than 30 years. It selectively blocks vascular and platelet 5-hydroxytryptamine 2 (5-HT2) receptors. This drug is marketed as a mixture of four stereoisomers, and so far there is no individual biological evaluation on the single isomers. The purpose of this study is to provide an improved method for the preparation of all four stereoisomers of naftidrofuryl, and more importantly, to distinguish them in terms of their binding affinity to 5-hydroxytryptamine 2A (5-HT2A) receptor. The bioassay results revealed that the C-2S configuration of naftidrofuryl was crucial for the binding affinity with 5-HT2A receptor, and the C-2′ configuration was less important for binding. In conclusion, our study may pave the way to develop single naftidrofuryl isomers with C-2S configuration as inhibitors of 5-HT2A receptor that have clinical significance as vasodilators and CNS agents. 相似文献
73.
Ryanne JM Lemmens Annick AA Timmermans Yvonne JM Janssen-Potten Rob JEM Smeets Henk AM Seelen 《BMC neurology》2012,12(1):1-17
Background
Loss of arm-hand performance due to a hemiparesis as a result of stroke or cerebral palsy (CP), leads to large problems in daily life of these patients. Assessment of arm-hand performance is important in both clinical practice and research. To gain more insight in e.g. effectiveness of common therapies for different patient populations with similar clinical characteristics, consensus regarding the choice and use of outcome measures is paramount. To guide this choice, an overview of available instruments is necessary. The aim of this systematic review is to identify, evaluate and categorize instruments, reported to be valid and reliable, assessing arm-hand performance at the ICF activity level in patients with stroke or cerebral palsy.Methods
A systematic literature search was performed to identify articles containing instruments assessing arm-hand skilled performance in patients with stroke or cerebral palsy. Instruments were identified and divided into the categories capacity, perceived performance and actual performance. A second search was performed to obtain information on their content and psychometrics.Results
Regarding capacity, perceived performance and actual performance, 18, 9 and 3 instruments were included respectively. Only 3 of all included instruments were used and tested in both patient populations. The content of the instruments differed widely regarding the ICF levels measured, assessment of the amount of use versus the quality of use, the inclusion of unimanual and/or bimanual tasks and the inclusion of basic and/or extended tasks.Conclusions
Although many instruments assess capacity and perceived performance, a dearth exists of instruments assessing actual performance. In addition, instruments appropriate for more than one patient population are sparse. For actual performance, new instruments have to be developed, with specific focus on the usability in different patient populations and the assessment of quality of use as well as amount of use. Also, consensus about the choice and use of instruments within and across populations is needed. 相似文献74.
75.
Background
Soluble guanylyl cyclase (sGC) plays a central role in nitric oxide (NO)-mediated signal transduction in the cardiovascular, nervous and gastrointestinal systems. Alternative RNA splicing has emerged as a potential mechanism to modulate sGC expression and activity. C-α1 sGC is an alternative splice form that is resistant to oxidation-induced protein degradation and demonstrates preferential subcellular distribution to the oxidized environment of endoplasmic reticulum (ER).Methodology/Principal Findings
Here we report that splicing of C-α1 sGC can be modulated by H2O2 treatment in BE2 neuroblastoma and MDA-MD-468 adenocarcinoma human cells. In addition, we show that the H2O2 treatment of MDA-MD-468 cells selectively decreases protein levels of PTBP1 and hnRNP A2/B1 splice factors identified as potential α1 gene splicing regulators by in silico analysis. We further demonstrate that down-regulation of PTBP1 by H2O2 occurs at the protein level with variable regulation observed in different breast cancer cells.Conclusions/Significance
Our data demonstrate that H2O2 regulates RNA splicing to induce expression of the oxidation-resistant C-α1 sGC subunit. We also report that H2O2 treatment selectively alters the expression of key splicing regulators. This process might play an important role in regulation of cellular adaptation to conditions of oxidative stress. 相似文献76.
Background
Over the last ten years, genomic selection has developed enormously. Simulations and results on real data suggest that breeding values can be predicted with high accuracy using genetic markers alone. However, to reach high accuracies, large reference populations are needed. In many livestock populations or even species, such populations cannot be established when traits are difficult or expensive to record, or when the population size is small. The value of genomic selection is then questionable.Methods
In this study, we compare traditional breeding schemes based on own performance or progeny information to genomic selection schemes, for which the number of phenotypic records is limiting. Deterministic simulations were performed using selection index theory. Our focus was on the equilibrium response obtained after a few generations of selection. Therefore, we first investigated the magnitude of the Bulmer effect with genomic selection.Results
Results showed that the reduction in response due to the Bulmer effect is the same for genomic selection as for selection based on traditional BLUP estimated breeding values, and is independent of the accuracy of selection. The reduction in response with genomic selection is greater than with selection based directly on phenotypes without the use of pedigree information, such as mass selection. To maximize the accuracy of genomic estimated breeding values when the number of phenotypic records is limiting, the same individuals should be phenotyped and genotyped, rather than genotyping parents and phenotyping their progeny. When the generation interval cannot be reduced with genomic selection, large reference populations are required to obtain a similar response to that with selection based on BLUP estimated breeding values based on own performance or progeny information. However, when a genomic selection scheme has a moderate decrease in generation interval, relatively small reference population sizes are needed to obtain a similar response to that with selection on traditional BLUP estimated breeding values.Conclusions
When the trait of interest cannot be recorded on the selection candidate, genomic selection schemes are very attractive even when the number of phenotypic records is limited, because traditional breeding requires progeny testing schemes with long generation intervals in those cases. 相似文献77.
Olga Nagy Margit Pál Andor Udvardy Christine AM Shirras Imre Boros Alan D Shirras Péter Deák 《Cell division》2012,7(1):1-15
Background
The spindle assembly checkpoint (SAC) inhibits anaphase progression in the presence of insufficient kinetochore-microtubule attachments, but cells can eventually override mitotic arrest by a process known as mitotic slippage or adaptation. This is a problem for cancer chemotherapy using microtubule poisons.Results
Here we describe mitotic slippage in yeast bub2?? mutant cells that are defective in the repression of precocious telophase onset (mitotic exit). Precocious activation of anaphase promoting complex/cyclosome (APC/C)-Cdh1 caused mitotic slippage in the presence of nocodazole, while the SAC was still active. APC/C-Cdh1, but not APC/C-Cdc20, triggered anaphase progression (securin degradation, separase-mediated cohesin cleavage, sister-chromatid separation and chromosome missegregation), in addition to telophase onset (mitotic exit), during mitotic slippage. This demonstrates that an inhibitory system not only of APC/C-Cdc20 but also of APC/C-Cdh1 is critical for accurate chromosome segregation in the presence of insufficient kinetochore-microtubule attachments.Conclusions
The sequential activation of APC/C-Cdc20 to APC/C-Cdh1 during mitosis is central to accurate mitosis. Precocious activation of APC/C-Cdh1 in metaphase (pre-anaphase) causes mitotic slippage in SAC-activated cells. For the prevention of mitotic slippage, concomitant inhibition of APC/C-Cdh1 may be effective for tumor therapy with mitotic spindle poisons in humans. 相似文献78.
Sharina IG Jelen F Bogatenkova EP Thomas A Martin E Murad F 《The Journal of biological chemistry》2008,283(22):15104-15113
Soluble guanylyl cyclase (sGC), a key protein in the NO/cGMP signaling pathway, is an obligatory heterodimeric protein composed of one alpha- and one beta-subunit. The alpha(1)/beta(1) sGC heterodimer is the predominant form expressed in various tissues and is regarded as the major isoform mediating NO-dependent effects such as vasodilation. We have identified three new alpha(1) sGC protein variants generated by alternative splicing. The 363 residue N1-alpha(1) sGC splice variant contains the regulatory domain, but lacks the catalytic domain. The shorter N2-alpha(1) sGC maintains 126 N-terminal residues and gains an additional 17 unique residues. The C-alpha(1) sGC variant lacks 240 N-terminal amino acids, but maintains a part of the regulatory domain and the entire catalytic domain. Q-PCR of N1-alpha(1), N2-alpha(1) sGC mRNA levels together with RT-PCR analysis for C-alpha(1) sGC demonstrated that the expression of the alpha(1) sGC splice forms vary in different human tissues indicative of tissue-specific regulation. Functional analysis of the N1-alpha(1) sGC demonstrated that this protein has a dominant-negative effect on the activity of sGC when coexpressed with the alpha(1)/beta(1) heterodimer. The C-alpha(1) sGC variant heterodimerizes with the beta(1) subunit and produces a fully functional NO- and BAY41-2272-sensitive enzyme. We also found that despite identical susceptibility to inhibition by ODQ, intracellular levels of the 54-kDa C-alpha(1) band did not change in response to ODQ treatments, while the level of 83 kDa alpha(1) band was significantly affected by ODQ. These studies suggest that modulation of the level and diversity of splice forms may represent novel mechanisms modulating the function of sGC in different human tissues. 相似文献
79.
The effect of food deprivation on ova transport, hormonal profiles and metabolic changes was studied in 20 crossbred multiparous
sows during their second oestrus after weaning. To determine the time of ovulation, transrectal ultrasonographic examination
was performed. The sows were divided into 2 groups, one control group (C-group), which was fed according to Swedish standards,
and one experimental group (E-group). The E-group sows were deprived of food from the first morning meal after ovulation until
slaughter. Blood samples were collected every second hour from about 12 h before expected ovulation in the second oestrus
after weaning until slaughter and were analysed for progesterone, prostaglandin F2α-metabolite, insulin, glucose, free fatty acids and triglycerides. All sows were slaughtered approximately 48 h after ovulation
and the genital tract was recovered. The isthmic part of the oviduct was divided into 3 equally long segments and flushed
separately with phosphate buffered saline (PBS). Uterine horns were also flushed with PBS. A significantly greater number
of ova were found in the first and second part of the isthmus in the E-group (p = 0.05) while in the C-group most of the ova
were found in the third part of the isthmus or the uterus (p = 0.01). The level of prostaglandin F2α-metabolite was significantly higher in the E-group compared with the C-group. The concentration of progesterone increased
in both groups after ovulation but there were no significant differences between the groups. The other blood parameters showed
that the food-deprived sows were in a catabolic state. The 48 h period of fasting results, directly or indirectly in an delayed
ova transport, which may be due to a delayed relaxation in the smooth circular muscle layer of the isthmus. 相似文献
80.
Martinus AM van Boekel Erik R Vossenaar Frank HJ van den Hoogen Walther J van Venrooij 《Arthritis research & therapy》2001,3(2):1-7
This review focuses on the mechanisms of stress response in the synovial tissue of rheumatoid arthritis. The major stress factors, such as heat stress, shear stress, proinflammatory cytokines and oxidative stress, are discussed and reviewed, focusing on their potential to induce a stress response in the synovial tissue. Several pathways of stress signalling molecules are found to be activated in the synovial membrane of rheumatoid arthritis; of these the most important examples are heat shock proteins, mitogen-activated protein kinases, stress-activated protein kinases and molecules involved in the oxidative stress pathways. The expression of these pathways in vitro and in vivo as well as the consequences of stress signalling in the rheumatoid synovium are discussed. Stress signalling is part of a cellular response to potentially harmful stimuli and thus is essentially involved in the process of synovitis. Stress signalling pathways are therefore new and promising targets of future anti-rheumatic therapies. 相似文献