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81.
Durand S Richard G Bontems F Uzan M 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(18):7073-7078
The bacteriophage T4-encoded RegB endoribonuclease is produced during the early stage of phage development and targets mostly (but not exclusively) the Shine-Dalgarno sequences of early genes. In this work, we show that the degradation of RegB-cleaved mRNAs depends on a functional T4 polynucleotide kinase/phosphatase (PNK). The 5'-OH produced by RegB cleavage is phosphorylated by the kinase activity of PNK. This modification allows host RNases G and E, with activity that is strongly stimulated by 5'-monophosphate termini, to attack mRNAs from the 5'-end, causing their destabilization. The PNK-dependent pathway of degradation becomes effective 5 min postinfection, consistent with our finding that several minutes are required for PNK to accumulate after infection. Our work emphasizes the importance of the nature of the 5' terminus for mRNA stability and depicts a pathway of mRNA degradation with 5'- to 3'-polarity in cells devoid of 5'-3' exonucleases. It also ascribes a role for T4 PNK during normal phage development. 相似文献
82.
P Villa S Soriano T Tsanova I Degano TF Higham F d'Errico L Backwell JJ Lucejko MP Colombini PB Beaumont 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(33):13208-13213
The transition from the Middle Stone Age (MSA) to the Later Stone Age (LSA) in South Africa was not associated with the appearance of anatomically modern humans and the extinction of Neandertals, as in the Middle to Upper Paleolithic transition in Western Europe. It has therefore attracted less attention, yet it provides insights into patterns of technological evolution not associated with a new hominin. Data from Border Cave (KwaZulu-Natal) show a strong pattern of technological change at approximately 44-42 ka cal BP, marked by adoption of techniques and materials that were present but scarcely used in the previous MSA, and some novelties. The agent of change was neither a revolution nor the advent of a new species of human. Although most evident in personal ornaments and symbolic markings, the change from one way of living to another was not restricted to aesthetics. Our analysis shows that: (i) at Border Cave two assemblages, dated to 45-49 and >49 ka, show a gradual abandonment of the technology and tool types of the post-Howiesons Poort period and can be considered transitional industries; (ii) the 44-42 ka cal BP assemblages are based on an expedient technology dominated by bipolar knapping, with microliths hafted with pitch from Podocarpus bark, worked suid tusks, ostrich eggshell beads, bone arrowheads, engraved bones, bored stones, and digging sticks; (iii) these assemblages mark the beginning of the LSA in South Africa; (iv) the LSA emerged by internal evolution; and (v) the process of change began sometime after 56 ka. 相似文献
83.
Chatelain FC Bichet D Douguet D Feliciangeli S Bendahhou S Reichold M Warth R Barhanin J Lesage F 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(14):5499-5504
TWIK1 belongs to the family of background K(+) channels with two pore domains. In native and transfected cells, TWIK1 is detected mainly in recycling endosomes. In principal cells in the kidney, TWIK1 gene inactivation leads to the loss of a nonselective cationic conductance, an unexpected effect that was attributed to adaptive regulation of other channels. Here, we show that TWIK1 ion selectivity is modulated by extracellular pH. Although TWIK1 is K(+) selective at neutral pH, it becomes permeable to Na(+) at the acidic pH found in endosomes. Selectivity recovery is slow after restoration of a neutral pH. Such hysteresis makes plausible a role of TWIK1 as a background channel in which selectivity and resulting inhibitory or excitatory influences on cell excitability rely on its recycling rate between internal acidic stores and the plasma membrane. TWIK1(-/-) pancreatic β cells are more polarized than control cells, confirming a depolarizing role of TWIK1 in kidney and pancreatic cells. 相似文献
84.
Background: In patients with outer retinal degeneration, a differential pupil response to long wavelength (red) versus short wavelength (blue) light stimulation has been previously observed. The goal of this study was to quantify differences in the pupillary re‐dilation following exposure to red versus blue light in patients with outer retinal disease and compare them with patients with optic neuropathy and with healthy subjects. Design: Prospective comparative cohort study. Participants: Twenty‐three patients with outer retinal disease, 13 patients with optic neuropathy and 14 normal subjects. Methods: Subjects were tested using continuous red and blue light stimulation at three intensities (1, 10 and 100 cd/m2) for 13 s per intensity. Pupillary re‐dilation dynamics following the brightest intensity was analysed and compared between the three groups. Main Outcome Measures: The parameters of pupil re‐dilation used in this study were: time to recover 90% of baseline size; mean pupil size at early and late phases of re‐dilation; and differential re‐dilation time for blue versus red light. Results: Patients with outer retinal disease showed a pupil that tended to stay smaller after light termination and thus had a longer time to recovery. The differential re‐dilation time was significantly greater in patients with outer retinal disease (median = 28.0 s, P < 0.0001) compared with controls and patients with optic neuropathy. Conclusions: A differential response of pupil re‐dilation following red versus blue light stimulation is present in patients with outer retinal disease but is not found in normal eyes or among patients with visual loss from optic neuropathy. 相似文献
85.
Usefulness of 2‐[18F]‐fluoro‐2‐deoxy‐d‐glucose–Positron Emission Tomography/Computed Tomography for Staging and Evaluation of Treatment Response in IgG4‐Related Disease: A Retrospective Multicenter Study 下载免费PDF全文
Mikael Ebbo Aurélie Grados Eric Guedj Delphine Gobert Cécile Colavolpe Mohamad Zaidan Agathe Masseau Fanny Bernard Jean‐Marie Berthelot Nathalie Morel François Lifermann Sylvain Palat Julien Haroche Xavier Mariette Bertrand Godeau Emmanuelle Bernit Nathalie Costedoat‐Chalumeau Thomas Papo Mohamed Hamidou Jean‐Robert Harlé Nicolas Schleinitz 《Arthritis care & research》2014,66(1):86-96
86.
87.
Is Going Beyond Rasch Analysis Necessary to Assess the Construct Validity of a Motor Function Scale?
Tiffanie Guillot Sylvain Roche Pascal Rippert Dalil Hamroun Jean Iwaz René Ecochard Carole Vuillerot 《Archives of physical medicine and rehabilitation》2018,99(9):1776-1782.e9
Objective
To examine whether a Rasch analysis is sufficient to establish the construct validity of the Motor Function Measure (MFM) and discuss whether weighting the MFM item scores would improve the MFM construct validity.Design
Observational cross-sectional multicenter study.Setting
Twenty-three physical medicine departments, neurology departments, or reference centers for neuromuscular diseases.Participants
Patients (N=911) aged 6 to 60 years with Charcot-Marie-Tooth disease (CMT), facioscapulohumeral dystrophy (FSHD), or myotonic dystrophy type 1 (DM1).Interventions
None.Main Outcome Measure(s)
Comparison of the goodness-of-fit of the confirmatory factor analysis (CFA) model vs that of a modified multidimensional Rasch model on MFM item scores in each considered disease.Results
The CFA model showed good fit to the data and significantly better goodness of fit than the modified multidimensional Rasch model regardless of the disease (P<.001). Statistically significant differences in item standardized factor loadings were found between DM1, CMT, and FSHD in only 6 of 32 items (items 6, 27, 2, 7, 9 and 17).Conclusions
For multidimensional scales designed to measure patient abilities in various diseases, a Rasch analysis might not be the most convenient, whereas a CFA is able to establish the scale construct validity and provide weights to adapt the item scores to a specific disease. 相似文献88.
89.
90.
Fabrice Compain Ana Babosan Sylvain Brisse Nathalie Genel Jennifer Audo Florent Ailloud Najiby Kassis-Chikhani Guillaume Arlet Dominique Decré 《Journal of clinical microbiology》2014,52(12):4377-4380
A single multiplex PCR assay targeting seven virulence factors and the wzi gene specific for the K1 and K2 capsular serotypes of Klebsiella pneumoniae was developed and tested on 65 clinical isolates, which included 45 isolates responsible for community-acquired severe human infections. The assay is useful for the surveillance of emerging highly virulent strains. 相似文献