153 research outputs found
Kinetoplastid RNA editing involves a 3ā² nucleotidyl phosphatase activity
Mitochondrial pre-messenger RNAs (pre-mRNAs) in African trypanosomes require RNA editing in order to mature into functional transcripts. The process involves the addition and/or removal of U nucleotides and is mediated by a high-molecular-mass complex, the editosome. Editosomes catalyze the reaction through an enzyme-driven pathway that includes endo/exoribonuclease, terminal uridylate transferase and RNA ligase activities. Here we show that editing involves an additional reaction step, a 3ā² nucleotidyl phosphatase activity. The activity is associated with the editing complex and we demonstrate that the editosomal proteins TbMP99 and TbMP100 contribute to the activity. Both polypeptides contain endo-exonuclease-phosphatase domains and we show that gene ablation of either one of the two polypeptides is compensated by the other protein. However, simultaneous knockdown of both genes results in trypanosome cells with reduced 3ā² nucleotidyl phosphatase and reduced editing activity. The data provide a rationale for the exoUase activity of the editosomal protein TbMP42, which generates nonligatable 3ā² phosphate termini. Opposing phosphates at the two pre-mRNA cleavage fragments likely function as a roadblock to prevent premature ligation
A Randomized Controlled Comparison of Image Quality
Background The purpose of the present study was to compare the image quality
of spinal magnetic resonance (MR) imaging performed on a high-field horizontal
open versus a short-bore MR scanner in a randomized controlled study setup.
Methods Altogether, 93 (80% women, mean age 53) consecutive patients underwent
spine imaging after random assignement to a 1-T horizontal open MR scanner
with a vertical magnetic field or a 1.5-T short-bore MR scanner. This patient
subset was part of a larger cohort. Image quality was assessed by determining
qualitative parameters, signal-to-noise (SNR) and contrast-to-noise ratios
(CNR), and quantitative contour sharpness. Results The image quality
parameters were higher for short-bore MR imaging. Regarding all sequences, the
relative differences were 39% for the mean overall qualitative image quality,
53% for the mean SNR values, and 34ā37% for the quantitative contour sharpness
(P<0.0001). The CNR values were also higher for images obtained with the
short-bore MR scanner. No sequence was of very poor (nondiagnostic) image
quality. Scanning times were significantly longer for examinations performed
on the open MR scanner (mean: 32Ā±22 min versus 20Ā±9 min; P<0.0001).
Conclusions In this randomized controlled comparison of spinal MR imaging with
an open versus a short-bore scanner, short-bore MR imaging revealed
considerably higher image quality with shorter scanning times
Prosthetic Valve Endocarditis with Bartonella washoensis in a Human European Patient and its Detection in Red Squirrels (Sciurus vulgaris)
Members of the genus Bartonella are fastidious Gram-negative facultative intracellular bacteria that are typically transmitted by arthropod vectors. Several Bartonella spp. have been found to cause culture-negative endocarditis in humans. Here, we report the case of a 75-year old German woman with prosthetic valve endocarditis due to Bartonella washoensis. The infecting agent was characterized by sequencing of six housekeeping genes (16S rRNA, ftsZ, gltA, groEL, ribC, rpoB) applying a multilocus sequence typing (MLST) approach. The 5097 bp of the concatenated housekeeping gene sequence from the patient were 99.0% identical to a B. washoensis strain from a red squirrel (Sciurus vulgaris orientis) from China. 39% (24/62) of red squirrel (S. vulgaris) samples from the Netherlands were positive for the B. washoensis gltA gene variant detected in the patient. This suggests that the red squirrel is the reservoir host for human infection in Europe
Proposed Mobility Assessments with Simultaneous Full-Body Inertial Measurement Units and Optical Motion Capture in Healthy Adults and Neurological Patients for Future Validation Studies: Study Protocol
Healthy adults and neurological patients show unique mobility patterns over the course of their lifespan and disease. Quantifying these mobility patterns could support diagnosing, tracking disease progression and measuring response to treatment. This quantification can be done with wearable technology, such as inertial measurement units (IMUs). Before IMUs can be used to quantify mobility, algorithms need to be developed and validated with age and disease-specific datasets. This study proposes a protocol for a dataset that can be used to develop and validate IMU-based mobility algorithms for healthy adults (18ā60 years), healthy older adults (>60 years), and patients with Parkinsonās disease, multiple sclerosis, a symptomatic stroke and chronic low back pain. All participants will be measured simultaneously with IMUs and a 3D optical motion capture system while performing standardized mobility tasks and non-standardized activities of daily living. Specific clinical scales and questionnaires will be collected. This study aims at building the largest dataset for the development and validation of IMU-based mobility algorithms for healthy adults and neurological patients. It is anticipated to provide this dataset for further research use and collaboration, with the ultimate goal to bring IMU-based mobility algorithms as quickly as possible into clinical trials and clinical routine
A global Staphylococcus aureus proteome resource applied to the in vivo characterization of host-pathogen interactions.
Data-independent acquisition mass spectrometry promises higher performance in terms of quantification and reproducibility compared to data-dependent acquisition mass spectrometry methods. To enable high-accuracy quantification of Staphylococcus aureus proteins, we have developed a global ion library for data-independent acquisition approaches employing high-resolution time of flight or Orbitrap instruments for this human pathogen. We applied this ion library resource to investigate the time-resolved adaptation of S. aureus to the intracellular niche in human bronchial epithelial cells and in a murine pneumonia model. In epithelial cells, abundance changes for more than 400āS. aureus proteins were quantified, revealing, e.g., the precise temporal regulation of the SigB-dependent stress response and differential regulation of translation, fermentation, and amino acid biosynthesis. Using an in vivo murine pneumonia model, our data-independent acquisition quantification analysis revealed for the first time the in vivo proteome adaptation of S. aureus. From approximately 2.15āĆā1
Die Reaktivierung von Schienenstrecken als Strategie der integrierten Raumentwicklung: Chancen nutzen und Hemmnisse Ć¼berwinden
Der Ausbau von Schienennetzen fĆ¼r den Personen- und GĆ¼terverkehr durch die Reaktivierung stillgelegter Strecken ist ein Gebot der Stunde! Schienenstrecken ermƶglichen nachhaltige MobilitƤt, gesellschaftliche Teilhabe und die Schaffung gleichwertiger LebensverhƤltnisse. Hierzu bedarf es einer grundsƤtzlich neuen und integrierten Ausrichtung der Raum- und Verkehrsplanung. Neben der dringend gebotenen Trassensicherung durch die Raumordnung mĆ¼ssen stillgelegte Schienenstrecken bezĆ¼glich ihrer Potenziale fĆ¼r die Orts- und Regionalentwicklung erkannt und reaktiviert werden. Stationen an Schienenstrecken kƶnnen insbesondere in lƤndlichen RƤumen wesentliche Entwicklungsimpulse erzeugen und als MobilitƤtsdrehscheiben fungieren. Dabei gilt es, bisherige Hindernisse zu Ć¼berwinden, indem beispielsweise neue volkswirtschaftliche BewertungsmaĆstƤbe angesetzt und neue Finanzierungsmodelle eingefĆ¼hrt werden.The expansion of rail networks for passenger and cargo services by reactivating disused rail lines is an urgent need of the hour! Rail lines enable sustainable mobility, social participation and the creation of equal living conditions. This requires a fundamentally new and integrated approach to spatial and transport planning. In addition to the urgent need to secure routes by means of spatial planning, disused railway lines must be recognized with regard to their potential for local and regional development and be reactivated. Stations on railway lines can generate significant development impulses, particularly in rural areas, and act as mobility hubs. Previous obstacles must be overcome, for example by applying new economic evaluation standards and introducing new financing models
Multisite phosphorylation is required for sustained interaction with GRKs and arrestins during rapid -opioid receptor desensitization
Copyright Ā© 2018 The Authors. G protein receptor kinases (GRKs) and -arrestins are key regulators of -opioid receptor (MOR) signaling and trafficking. We have previously shown that high-efficacy opioids such as DAMGO stimulate a GRK2/3-mediated multisite phosphorylation of conserved C-terminal tail serine and threonine residues, which facilitates internalization of the receptor. In contrast, morphine-induced phosphorylation of MOR is limited to Ser375 and is not sufficient to drive substantial receptor internalization. We report how specific multisite phosphorylation controlled the dynamics of GRK and -arrestin interactions with MOR and show how such phosphorylation mediated receptor desensitization. We showed that GRK2/3 was recruited more quickly than was -arrestin to a DAMGO-activated MOR. -Arrestin recruitment required GRK2 activity and MOR phosphorylation, but GRK recruitment also depended on the phosphorylation sites in the C-terminal tail, specifically four serine and threonine residues within the 370TREHPSTANT379 motif. Our results also suggested that other residues outside this motif participated in the initial and transient recruitment of GRK and -arrestins. We identified two components of high-efficacy agonist desensitization of MOR: a sustained component, which required GRK2-mediated phosphorylation and a potential soluble factor, and a rapid component, which was likely mediated by GRK2 but independent of receptor phosphorylation. Elucidating these complex receptor-effector interactions represents an important step toward a mechanistic understanding of MOR desensitization that leads to the development of tolerance and dependence
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