343 research outputs found
Recommended from our members
Spire stimulates nucleation by Cappuccino and binds both ends of actin filaments.
The actin nucleators Spire and Cappuccino synergize to promote actin assembly, but the mechanism of their synergy is controversial. Together these proteins promote the formation of actin meshes, which are conserved structures that regulate the establishment of oocyte polarity. Direct interaction between Spire and Cappuccino is required for oogenesis and for in vitro synergistic actin assembly. This synergy is proposed to be driven by elongation and the formation of a ternary complex at filament barbed ends, or by nucleation and interaction at filament pointed ends. To mimic the geometry of Spire and Cappuccino in vivo, we immobilized Spire on beads and added Cappuccino and actin. Barbed ends, protected by Cappuccino, grow away from the beads while pointed ends are retained, as expected for nucleation-driven synergy. We found that Spire is sufficient to bind barbed ends and retain pointed ends of actin filaments near beads and we identified Spire's barbed-end binding domain. Loss of barbed-end binding increases nucleation by Spire and synergy with Cappuccino in bulk pyrene assays and on beads. Importantly, genetic rescue by the loss-of-function mutant indicates that barbed-end binding is not necessary for oogenesis. Thus, increased nucleation is a critical element of synergy both in vitro and in vivo
Recommended from our members
Federal Depository Library Program: Issues for Congress
A history and overview of current issues regarding the Federal Depository Library Program (FDLP)
Patient and family communication during consultation visits: The effects of a decision aid for treatment decision-making for localized prostate cancer
To analyze the effects of a decision aid on improving patients’ and family members’ information giving and question asking during consultations for prostate cancer treatment decision-making
Stroke Ready Intervention: Community Engagement to Decrease Prehospital Delay
Background: Time-limited acute stroke treatments are underused, primarily due to prehospital delay. One approach to decreasing prehospital delay is to increase stroke preparedness, the ability to recognize stroke, and the intention to immediately call emergency medical services, through community engagement with high-risk communities. Methods and Results: Our community-academic partnership developed and tested "Stroke Ready," a peer-led, workshop-based, health behavior intervention to increase stroke preparedness among African American youth and adults in Flint, Michigan. Outcomes were measured with a series of 9 stroke and nonstroke 1-minute video vignettes; after each video, participants selected their intended response (primary outcome) and symptom recognition (secondary outcome), receiving 1 point for each appropriate stroke response and recognition. We assessed differences between baseline and posttest appropriate stroke response, which was defined as intent to call 911 for stroke vignettes and not calling 911 for nonstroke, nonemergent vignettes and recognition of stroke. Outcomes assessments were performed before workshop 1 (baseline), at the conclusion of workshop 2 (immediate post-test), and 1Â month later (delayed post-test). A total of 101 participants completed the baseline assessment (73 adults and 28 youths), 64 completed the immediate post-test, and 68 the delayed post-test. All participants were African American. The median age of adults was 56 (interquartile range 35-65) and of youth was 14 (interquartile range 11-16), 65% of adults were women, and 50% of youths were women. Compared to baseline, appropriate stroke response was improved in the immediate post-test (4.4 versus 5.2, P < 0.01) and was sustained in the delayed post-test (4.4 versus 5.2, P < 0.01). Stroke recognition did not change in the immediate post-test (5.9 versus 6.0, P=0.34), but increased in the delayed post-test (5.9 versus 6.2, P=0.04). Conclusions: Stroke Ready increased stroke preparedness, a necessary step toward increasing acute stroke treatment rates
A rapid systematic review of breakthrough pain definitions and descriptions
Background Breakthrough pain is common in life-limiting conditions and at end-of-life. Despite over 30 years of study, there is little consensus regarding the definition and characteristics of breakthrough pain. Objective This study aims to update and expand a 2010 systematic review by Haugen and colleagues to identify (1) all definitions of breakthrough pain and (2) all descriptions and classifications of breakthrough pain reported by patients, caregivers, clinicians, and experts. Design This rapid systematic review followed the Cochrane Rapid Review Methods Group guidelines. A protocol is published on PROSPERO (CRD42019155583). Data sources CINAHL, MEDLINE, PsycINFO, and the Web of Science were searched for breakthrough pain terms from the inception dates of each database to 26th August 2022. Results We identified 65 studies that included data on breakthrough pain definitions, descriptions, or classifications from patients ( n = 30), clinicians ( n = 6), and experts ( n = 29), but none with data from caregivers. Most experts proposed that breakthrough pain was a sudden, severe, brief pain occurring in patients with adequately controlled mild-moderate background pain. However, definitions varied and there was no consensus. Pain characteristics were broadly similar across studies though temporal factors varied widely. Experts classified breakthrough pain into nociceptive, neuropathic, visceral, somatic, or mixed types. Patients with breakthrough pain commonly experienced depression, anxiety, and interference with daily life. Conclusions Despite ongoing efforts, there is still no consensus on the definition of breakthrough pain. A compromise is needed on breakthrough pain nomenclature to collect reliable incidence and prevalence data and to inform further refinement of the construct
Peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) restores carbapenem susceptibility to NDM-1-positive pathogens in vitro and in vivo
The objective of this study was to test the efficacy of an inhibitor of the New Delhi metallo-β- lactamase (NDM-1). Inhibiting expression of this type of antibiotic-resistance gene has the potential to restore antibiotic susceptibility in all bacteria carrying the gene.Methods: We have constructed a peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) that selectively inhibits the expression of NDM-1 and examined its ability to restore susceptibility to meropenem in vitro and in vivo.Results:In vitro, the PPMO reduced the MIC of meropenem for three different genera of pathogens that express NDM-1. In a murine model of lethal E. coli sepsis, the PPMO improved survival (92%) and reduced systemic bacterial burden when given concomitantly with meropenem.Conclusions: These data show that a PPMO can restore antibiotic susceptibility in vitro and in vivo and that the combination of PPMO and meropenem may have therapeutic potential against certain class B carbapenem- resistant infections in multiple genera of Gram-negative pathogens
Imaging Radiation-Induced Normal Tissue Injury
Technological developments in radiation therapy and other cancer therapies have led to a progressive increase in five-year survival rates over the last few decades. Although acute effects have been largely minimized by both technical advances and medical interventions, late effects remain a concern. Indeed, the need to identify those individuals who will develop radiation-induced late effects, and to develop interventions to prevent or ameliorate these late effects is a critical area of radiobiology research. In the last two decades, preclinical studies have clearly established that late radiation injury can be prevented/ameliorated by pharmacological therapies aimed at modulating the cascade of events leading to the clinical expression of radiation-induced late effects. These insights have been accompanied by significant technological advances in imaging that are moving radiation oncology and normal tissue radiobiology from disciplines driven by anatomy and macrostructure to ones in which important quantitative functional, microstructural, and metabolic data can be noninvasively and serially determined. In the current article, we review use of positron emission tomography (PET), single photon emission tomography (SPECT), magnetic resonance (MR) imaging and MR spectroscopy to generate pathophysiological and functional data in the central nervous system, lung, and heart that offer the promise of, (1) identifying individuals who are at risk of developing radiation-induced late effects, and (2) monitoring the efficacy of interventions to prevent/ameliorate them
Quantitative optical coherence tomography angiography of vascular abnormalities in the living human eye
Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of pathogenesis. In choroideremia, OCT's ability to show choroidal and retinal vascular dysfunction separately may be valuable in predicting progression and assessing treatment response. OCT angiography shows promise as a noninvasive alternative to dye-based angiography for highly detailed, in vivo, 3D, quantitative evaluation of retinal vascular abnormalities.National Institutes of Health (U.S.) (Grant R01-EY023285)National Institutes of Health (U.S.) (Grant R01-EY024544)National Institutes of Health (U.S.) (Grant DP3 DK104397)National Institutes of Health (U.S.) (Grant R01-EY11289)National Institutes of Health (U.S.) (Grant K08-EY021186)National Institutes of Health (U.S.) (Grant T32-EY23211)National Institutes of Health (U.S.) (Grant P30-EY010572)Clinical and Translational Science Award Grant UL1TR000128Research to Prevent Blindness, Inc. (United States) (Grant and Career Development Award CD-NMT-0914-0659-OHSU)United States. Air Force Office of Scientific Research (Foundation Fighting Blindness Career Development Award FA9550-10-1-0551)German Research Foundation (Grant DFG-HO-1791/11-1)German Research Foundation (Grant DFG-GSC80-SAOT
Fast motif recognition via application of statistical thresholds
Background: Improving the accuracy and efficiency of motif recognition is an important computational challenge that has application to detecting transcription factor binding sites in genomic data. Closely related to motif recognition is the Consensus String decision problem that asks, given a parameter d and a set of â„“-length strings S = {s1,...,sn}, whether there exists a consensus string that has Hamming distance at most d from any string in S. A set of strings S is pairwise bounded if the Hamming distance between any pair of strings in S is at most 2d. It is trivial to determine whether a set is pairwise bounded, and a set cannot have a consensus string unless it is pairwise bounded. We use Consensus String to determine whether or not a pairwise bounded set has a consensus. Unfortunately, Consensus String is NP-complete. The lack of an efficient method to solve the Consensus String problem has caused it to become a computational bottleneck in MCL-WMR, a motif recognition program capable of solving difficult motif recognition problem instances. Results: We focus on the development of a method for solving Consensus String quickly with a small probability of error. We apply this heuristic to develop a new motif recognition program, sMCL-WMR, which has impressive accuracy and efficiency. We demonstrate the performance of sMCL-WMR in detecting weak motifs in large data sets and in real genomic data sets, and compare the performance to other leading motif recognitio
- …