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991.
992.
Stephanie Hamill Sandra L. Wolin Karin M. Reinisch 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(34):15045-15050
The Trf4p/Air2p/Mtr4p polyadenylation (TRAMP) complex recognizes aberrant RNAs in Saccharomyces cerevisiae and targets them for degradation. A TRAMP subcomplex consisting of a noncanonical poly(A) RNA polymerase in the Pol ß superfamily of nucleotidyl transferases, Trf4p, and a zinc knuckle protein, Air2p, mediates initial substrate recognition. Trf4p and related eukaryotic poly(A) and poly(U) polymerases differ from other characterized enzymes in the Pol ß superfamily both in sequence and in the lack of recognizable nucleic acid binding motifs. Here we report, at 2.7-Å resolution, the structure of Trf4p in complex with a fragment of Air2p comprising two zinc knuckle motifs. Trf4p consists of a catalytic and central domain similar in fold to those of other noncanonical Pol β RNA polymerases, and the two zinc knuckle motifs of Air2p interact with the Trf4p central domain. The interaction surface on Trf4p is highly conserved across eukaryotes, providing evidence that the Trf4p/Air2p complex is conserved in higher eukaryotes as well as in yeast and that the TRAMP complex may also function in RNA surveillance in higher eukaryotes. We show that Air2p, and in particular sequences encompassing a zinc knuckle motif near its N terminus, modulate Trf4p activity, and we present data supporting a role for this zinc knuckle in RNA binding. Finally, we show that the RNA 3′ end plays a role in substrate recognition. 相似文献
993.
IntroductionThe peripherally inserted central catheter (PICC) is being used more frequently in pediatric populations in both hospital and home care settings in order to provide secure vascular access. In 2007, the Power PICC was introduced to pediatric populations. In contrast to traditional PICCs, the power injectable PICC withstands higher flow rates and can deliver contrast injections. Although effectiveness studies of power injectable PICCs have been performed in adults, only limited published research is available regarding pediatric populations.PurposeThis study aimed to develop criteria for identifying the ideal pediatric candidate for the power injectable PICC. A secondary aim was to identify contraindications and barriers to power injectable catheter use in pediatric populations.MethodsRetrospective and prospective chart reviews were used to analyze complication rates for 97 power injectable PICCs placed in patients aged 4 months to 17 years.ResultsA low incidence of catheter complications was identified during and post- insertion. Our documented infection rate of 1.30 per 1000 catheter days was similar to the infection rate of 1.27 per 1000 catheter days found in the Abedin & Kapoor (2008) study.DiscussionThe introduction into a pediatric hospital of power injectable PICCs for power injection scans for contrast injection was safe and effective in patients with many disease processes.ConclusionIn properly selected pediatric patients, the power injectable PICC is not associated with an increased risk to thrombosis or infection and can improve patient outcome. 相似文献
994.
995.
Warren G. Darling Marc A. Pizzimenti Diane L. Rotella Stephanie M. Hynes Jizhi Ge Kimberly S. Stilwell-Morecraft Tyler Vanadurongvan David W. McNeal Kathryn M. Solon-Cline Robert J. Morecraft 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2010,202(3):529-542
The purpose of this study was to determine if recovery of neurologically impaired hand function following isolated motor cortex
injury would occur without constraint of the non-impaired limb, and without daily forced use of the impaired limb. Nine monkeys
(Macaca mulatta) received neurosurgical lesions of various extents to arm representations of motor cortex in the hemisphere contralateral
to the preferred hand. After the lesion, no physical constraints were placed on the ipsilesional arm/hand and motor testing
was carried out weekly with a maximum of 40 attempts in two fine motor tasks that required use of the contralesional hand
for successful food acquisition. These motor tests were the only “forced use” of the contralesional hand. We also tested regularly
for spontaneous use of the contralesional hand in a fine motor task in which either hand could be used for successful performance.
This minimal intervention was sufficient to induce recovery of the contralesional hand to such a functional level that eight
of the monkeys chose to use that hand on some trials when either hand could be used. Percentage use of the contralesional
hand (in the task when either hand could be used) varied considerably among monkeys and was not related to lesion volume or
recovery of motor skill. These data demonstrate a remarkable capacity for recovery of spontaneous use of the impaired hand
following localized frontal lobe lesions. Clinically, these observations underscore the importance of therapeutic intervention
to inhibit the induction of the learned nonuse phenomenon after neurological injury. 相似文献
996.
Urs Granacher Irene Wolf Anja Wehrle Stephanie Bridenbaugh Reto W Kressig 《Journal of neuroengineering and rehabilitation》2010,7(1):56
Background
Muscle fatigue and dual-task walking (e.g., concurrent performance of a cognitive interference (CI) while walking) represent major fall risk factors in young and older adults. Thus, the objectives of this study were to examine the effects of muscle fatigue on gait characteristics under single and dual-task conditions in young and older adults and to determine the impact of muscle fatigue on dual-task costs while walking. 相似文献997.
998.
Hyperactivity of the hypothalamic–pituitary–adrenal (HPA) axis is a marked feature of anorexia nervosa. Using a modified version of the activity‐based animal model of anorexia nervosa, we examine whether factors known to affect HPA axis activity influence the development of activity‐based anorexia (ABA). Male and female rats were subjected to maternal separation or handling procedures during the first two postnatal weeks and tested in a mild version of the ABA paradigm, comprised of 2‐hr daily running wheel access followed by 1‐hr food access, either in adolescence or adulthood. Compared to handled females, maternally separated females demonstrated greater increases in wheel running and a more pronounced running‐induced suppression of food intake during adolescence, but not in adulthood. In contrast, it was only in adulthood that wheel running produced more prolonged anorexic effects in maternally separated than in handled males. These findings highlight the interplay between early postnatal treatment, sex of the animal, and developmental age on running, food intake, and rate of body weight loss in a mild version of the ABA paradigm. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 679–695, 2009. 相似文献
999.
Stephanie E. Gline Dian‐Han Kuo Alberto Stolfi David A. Weisblat 《Developmental dynamics》2009,238(12):3139-3151
Knowing the normal patterns of embryonic cell proliferation, migration, and differentiation is a cornerstone for understanding development. Yet for most species, the precision with which embryonic cell lineages can be determined is limited by technical considerations (the large numbers of cells, extended developmental times, opacity of the embryos), and these are exacerbated by the inherent variability of the lineages themselves. Here, we present an improved method of cell lineage tracing in the leech Helobdella, driving the expression of a nuclearly localized histone H2B:GFP (green fluorescent protein) fusion protein in selected lineages by microinjection of a plasmid vector. This construct generates a long lasting and minimally mosaic signal with single cell resolution, and does not disrupt the development of most lineages tested. We have validated this technique by elucidating details of cell lineages contributing to segmental and prostomial tissues that could not be observed with standard dextran lineage tracers. Developmental Dynamics 238:3139–3151, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
1000.