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Rotmann A Vékony N Gassner D Niegisch G Strand D Martiné U Closs EI 《The Biochemical journal》2006,395(1):117-123
We have previously shown that activation of PKC (protein kinase C) results in internalization of hCAT-1 [human CAT-1 (cationic amino acid transporter 1)] and a decrease in arginine transport [Rotmann, Strand, Martiné and Closs (2004) J. Biol. Chem. 279, 54185-54192]. However, others found increased transport rates for arginine in response to PKC activation, suggesting a differential effect of PKC on different CAT isoforms. Therefore we investigated the effect of PKC on hCAT-3, an isoform expressed in thymus, brain, ovary, uterus and mammary gland. In Xenopus laevis oocytes and human U373MG glioblastoma cells, hCAT-3-mediated L-arginine transport was significantly reduced upon treatment with compounds that activate classical PKC. In contrast, inactive phorbol esters and an activator of novel PKC isoforms had no effect. PKC inhibitors (including the PKCalpha-preferring Ro 31-8280) reduced the inhibitory effect of the PKC-activating compounds. Microscopic analyses revealed a PMA-induced reduction in the cell-surface expression of fusion proteins between hCAT-3 and enhanced green fluorescent protein expressed in X. laevis oocytes and glioblastoma cells. Western-blot analysis of biotinylated surface proteins demonstrated a PMA-induced decrease in hCAT-3 in the plasma membrane, but not in total protein lysates. Pretreatment with a PKC inhibitor also reduced this PMA effect. It is concluded that similar to hCAT-1, hCAT-3 activity is decreased by PKC via reduction of transporter molecules in the plasma membrane. Classical PKC isoforms seem to be responsible for this effect. 相似文献
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Davina de C.M Simoes David McNeill Bjorn Kristiansen Michael Mattey 《FEMS microbiology letters》1997,147(1):151-156
The molecular mass of esterases usually falls in the range of 20–160 kDa, although an esterase of 5.7 kDa from Candida lipolytica has been described. Three other enzymes smaller than 10 kDa have been reported, all of which were more thermostable than their higher molecular mass counterparts. This paper describes the purification of an extracellular esterase hydrolysing fluorescein dibutyrate from Bacillus stearothermophilus NCIMB 13335. The esterase had a molecular mass of 1.57 kDa when analysed by SDS-PAGE, gel filtration and MALDI-TOF spectrometry. This enzyme retained more than 90% of its activity after incubation at 90°C for 2 h. 相似文献
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Gorton D Norton R Layton R Smith H Ketheesan N 《Microbes and infection / Institut Pasteur》2005,7(3):421-426
The fibronectin-binding proteins (FnBPs) PrtF1 and PrtF2 are considered to be major group A streptococcal virulence factors, mediating adherence to and internalisation of host cells. The present study investigated an association between the presence of prtF1 and prtF2 genes and internalisation efficiency in group A streptococci (GAS) isolated from patients with invasive disease. Of the 80 isolates tested, 58 (73%) had prtF1 and 71 (89%) possessed prtF2. Three isolates (4%) had neither gene, seven (9%) had prtF1 only, 19 (24%) had prtF2 only and 51 isolates (64%) had both prtF1 and prtF2. prtF2-positive isolates internalised up to three times more efficiently than isolates that had prtF1 alone (P<0.001), and 1.5-fold better than isolates that had neither gene. No significant association was found between internalisation efficiency and presence of the prtF1 gene. Analysis of the fibronectin-binding repeat domain (FBRD) of prtF2 revealed that this gene can contain 2, 3, 4 or 5 repeat regions and that five repeat regions conferred very high internalisation efficiency in invasive GAS isolates. 相似文献
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Kristen L. Hollands Trudy A. Pelton Andrew Wimperis Diane Whitham Wei Tan Sue Jowett Catherine M. Sackley Alan M. Wing Sarah F. Tyson Jonathan Mathias Marianne Hensman Paulette M. van Vliet 《PloS one》2015,10(10)
Objectives
Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke.Design
This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation servicesParticipants
Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairmentsIntervention
Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks.Main outcome measures: Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up.Results
Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms.Conclusions
Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention.Trial Registration
Clinicaltrials.gov NCT01600391 相似文献28.
Introduction
The benefits of clinical trials registration include improved transparency on clinical trials for healthcare workers and patients, increased accountability of trialists, the potential to address publication bias and selective reporting, and possibilities for research collaboration and prioritization. However, poor quality of information in registered records of trials has been found to undermine these benefits in the past. Trialists'' increasing experience with trial registration and recent developments in registration systems may have positively affected data quality. This study was conducted to investigate whether the quality of registration has improved.Methods
We repeated a study from 2009, using the same methods and the same research team. A random sample of 400 records of clinical trials that were registered between 01/01/2012 and 01/01/2013 was taken from the International Clinical Trials Registry Platform (ICTRP) and assessed for the quality of information on 1) contact details, 2) interventions and 3) primary outcomes. Results were compared to the equivalent assessments from our previous study.Results
There was a small and not statistically significant increase from 81.0% to 85.5% in the percentage of records that provided a name of a contact person. There was a significant increase from 68.7% to 74.9% in the number of records that provided either an email address or a telephone number. There was a significant increase from 44.2% to 51.9% in the number of intervention arms that were complete in registering intervention specifics. There was a significant increase from 38.2% to 57.6% in the number of primary outcomes that were specific measures with a meaningful timeframe. Approximately half of all trials continued to be retrospectively registered.Discussion
There have been small but significant improvements in the quality of registration since 2009. Important problems with quality remain and continue to constitute an impediment to the meaningful utilization of registered trial information. 相似文献29.
Obesity is associated with chronic inflammation and elevated levels of IL-6. The role of IL-6 in induction of acute-phase proteins and modulation of hematological responses has been demonstrated in models of inflammation and aging, but not in obesity. We hypothesized that IL-6 is necessary to regulate the acute-phase response and hematological changes associated with diet-induced obesity (DIO) in mice. Feeding a 60%kcal/fat diet for 13 weeks to C57BL6 WT male mice induced a significant increase in IL-6 expression in visceral adipose tissue (VAT), but not liver, compared to mice fed chow diet. Significantly elevated IL-6 levels were present in the peritoneal lavage fluid, but not plasma, of DIO compared to lean mice. A comparable degree of obesity, hepatomegaly, hyperleptinemia, VAT inflammation and insulin resistance was observed in DIO WT and IL-6 KO mice compared to WT and KO mice fed chow diet. Significant leukocytosis was observed in DIO WT but not DIO KO mice compared to lean groups. A significant reduction in platelet counts, without alterations in platelet size, percentage of circulating reticulated platelets and number of bone marrow megakaryocytes, was present in DIO KO mice compared to each other group. Hepatic expression of thrombopoietin was comparable in each group, with DIO WT and KO mice having reduced VAT expression compared to lean mice. Lean KO mice had significantly elevated plasma levels of thrombopoietin compared to each other group, whereas liver-associated thrombopoietin levels were comparable in each group. Deficiency of IL-6 resulted in blunted hepatic induction of the acute-phase protein serum amyloid A-1, whereas expression of hepcidin-1 and -2, LPS-binding protein, ceruloplasmin, plasminogen activator inhibitor-1 and thrombospondin-1 was IL-6-independent. In conclusion, in the absence of overt metabolic alterations, IL-6 modulates leukocytosis, thrombopoiesis and induction of SAA-1, but not other acute-phase proteins in obese mice. 相似文献
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