By engineering the point-spread function (PSF) of single molecules, different fluorophore species can be imaged simultaneously and distinguished by their unique PSF patterns. Here, we insert a silicon-dioxide phase plate at the Fourier plane of the detection path of a wide-field fluorescence microscope to produce distinguishable PSFs (X-PSFs) at different wavelengths. We demonstrate that the resulting PSFs can be localized spatially and spectrally using a maximum-likelihood estimation algorithm and can be utilized for hyper-spectral super-resolution microscopy of biological samples.
View Article and Find Full Text PDFCoronavirus disease 2019 (COVID-19) is a respiratory infection caused by severe acute respiratory syndrome coronavirus 2. The virus binds to angiotensinogen converting enzyme 2 (ACE2), which mediates viral entry into mammalian cells. COVID-19 is notably severe in the elderly and in those with underlying chronic conditions.
View Article and Find Full Text PDFFine-scale molecular architecture is critical for nervous system and other biological functions. Methods to visualize these nanoscale structures would benefit from enhanced accessibility, throughput, and tissue compatibility. Here, we report RAIN-STORM, a rapid and scalable nanoscopic imaging optimization approach that improves three-dimensional visualization for subcellular targets in tissue at depth.
View Article and Find Full Text PDFCoronavirus disease 2019 (COVID19) is a respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originating in Wuhan, China in 2019. The disease is notably severe in elderly and those with underlying chronic conditions. A molecular mechanism that explains why the elderly are vulnerable and why children are resistant is largely unknown.
View Article and Find Full Text PDFBackground: In the Carotid Revascularization Endarterectomy versus Stent Trial (CREST), carotid artery atherosclerotic lesion length and nature of the lesions were important factors that predicted the observed difference in stroke rates between carotid endarterectomy and carotid artery stenting (CAS). Additional patient-related factors influencing CAS outcomes in CREST included age and symptomatic status. The importance of the operator's proficiency and its influence on periprocedural complications have not been well defined.
View Article and Find Full Text PDFBackground: In the Carotid Revascularization Endarterectomy versus Stenting Trial, we found no significant difference between the stenting group and the endarterectomy group with respect to the primary composite end point of stroke, myocardial infarction, or death during the periprocedural period or any subsequent ipsilateral stroke during 4 years of follow-up. We now extend the results to 10 years.
Methods: Among patients with carotid-artery stenosis who had been randomly assigned to stenting or endarterectomy, we evaluated outcomes every 6 months for up to 10 years at 117 centers.
The recycling of synaptic vesicles requires the recovery of vesicle proteins and membrane. Members of the stonin protein family (Drosophila Stoned B, mammalian stonin 2) have been shown to link the synaptic vesicle protein synaptotagmin to the endocytic machinery. Here we characterize the unc-41 gene, which encodes the stonin ortholog in the nematode Caenorhabditis elegans.
View Article and Find Full Text PDFThe vacuolar-type ATPase (V-ATPase) is a proton pump composed of two sectors, the cytoplasmic V(1) sector that catalyzes ATP hydrolysis and the transmembrane V(o) sector responsible for proton translocation. The transmembrane V(o) complex directs the complex to different membranes, but also has been proposed to have roles independent of the V(1) sector. However, the roles of the V(1) sector have not been well characterized.
View Article and Find Full Text PDFBackground: Complexin binds the SNARE complex at synapses and regulates exocytosis, but genetic studies indicate contradictory roles: in flies it predominantly inhibits synaptic vesicle fusion, whereas in mice it promotes evoked responses.
Results: Here we characterize the complexin mutant in the nematode Caenorhabditis elegans and reveal bipolar functions in neurotransmission: complexin inhibits spontaneous fusion of synaptic vesicles but is also essential for evoked responses. Complexin mutants exhibit a doubling of vesicle fusion in the absence of extracellular calcium.
A complete portrait of a cell requires a detailed description of its molecular topography: proteins must be linked to particular organelles. Immunocytochemical electron microscopy can reveal locations of proteins with nanometer resolution but is limited by the quality of fixation, the paucity of antibodies and the inaccessibility of antigens. Here we describe correlative fluorescence electron microscopy for the nanoscopic localization of proteins in electron micrographs.
View Article and Find Full Text PDFBackground: Carotid-artery stenting and carotid endarterectomy are both options for treating carotid-artery stenosis, an important cause of stroke.
Methods: We randomly assigned patients with symptomatic or asymptomatic carotid stenosis to undergo carotid-artery stenting or carotid endarterectomy. The primary composite end point was stroke, myocardial infarction, or death from any cause during the periprocedural period or any ipsilateral stroke within 4 years after randomization.
The success of carotid artery stenting in preventing stroke requires a low risk of periprocedural stroke and death. A comprehensive training and credentialing process was prerequisite to the randomized Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) to assemble a competent team of interventionalists with low periprocedural event rates. Interventionalists submitted cases to a multidisciplinary Interventional Management Committee.
View Article and Find Full Text PDFBackground And Purpose: Several carotid endarterectomy randomized, controlled trials and series have reported higher perioperative stroke and death rates for women compared with men. The potential for this same relationship with carotid artery stenting was examined in the lead-in phase of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST).
Methods: CREST compares efficacy of carotid endarterectomy and carotid artery stenting in preventing stroke, myocardial infarction, and death in the periprocedural period and ipsilateral stroke over the follow-up period.
Serotonin modulates behavioral plasticity in both vertebrates and invertebrates and in Caenorhabditis elegans regulates key behaviors, including locomotion, aversive learning and olfaction through at least four different 5-HT receptors. In the present study, we examined the serotonergic stimulation of aversive responses to dilute octanol in animals containing null alleles of these 5-HT receptors. Both ser-1 and mod-1 null animals failed to increase sensitivity to dilute octanol on food/5-HT, in contrast to wild-type, ser-4 or ser-7 null animals.
View Article and Find Full Text PDFSerotonin (5-HT) regulates key processes in both vertebrates and invertebrates. Previously, four 5-HT receptors that contributed to the 5-HT modulation of egg laying were identified in Caenorhabditis elegans. Therefore, to assess potential receptor interactions, we generated animals containing combinations of null alleles for each receptor, especially animals expressing only individual 5-HT receptors.
View Article and Find Full Text PDFCarotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed to have fewer complications than CAS for primary atherosclerotic (PA) lesions. It has been proposed that interventionalists may limit themselves to CAS for RS initially, while they gain additional experience during their learning curve. However, there are few studies objectively comparing the outcomes of the two groups of patients to substantiate this assumption.
View Article and Find Full Text PDFObjectives: The relative efficacy and safety of endarterectomy and stenting in patients with carotid stenosis remain unclear. In this review we synthesize the available evidence derived from randomized controlled trials (RCTs) that compared the two procedures in terms of the risks of death, stroke (disabling and nondisabling), and nonfatal myocardial infarction.
Methods: We searched for RCTs in MEDLINE, EMBASE, Current Contents, and Cochrane CENTRAL; expert files, and bibliographies of included articles.
The Society for Vascular Surgery (SVS) appointed a committee of experts to formulate evidence-based clinical guidelines for the management of carotid stenosis. In formulating clinical practice recommendations, the committee used systematic reviews to summarize the best available evidence and the GRADE scheme to grade the strength of recommendations (GRADE 1 for strong recommendations; GRADE 2 for weak recommendations) and rate the quality of evidence (high, moderate, low, and very low quality). In symptomatic and asymptomatic patients with low-grade carotid stenosis (<50% in symptomatic and <60% in asymptomatic patients), we recommend optimal medical therapy rather than revascularization (GRADE 1 recommendation, high quality evidence).
View Article and Find Full Text PDFObjectives: Ultrasound velocity criteria for the diagnosis of in-stent restenosis in patients undergoing carotid artery stenting (CAS) are not well established. In the present study, we test whether ultrasound velocity measurements correlate with increasing degrees of in-stent restenosis in patients undergoing CAS and develop customized velocity criteria to identify residual stenosis > or =20%, in-stent restenosis > or =50%, and high-grade in-stent restenosis > or =80%.
Methods: Carotid angiograms performed at the completion of CAS were compared with duplex ultrasound (DUS) imaging performed immediately after the procedure.
Objectives: Factors predicting in-stent restenosis (ISR) and future need for target lesion revascularization (TLR) after carotid artery stenting (CAS) remain undetermined. We hypothesized that the patterns of restenotic lesions may provide prognostic information. In this study, we developed an ultrasound classification scheme for ISR based on lesion length and distribution and assessed factors that may predict the need for TLR.
View Article and Find Full Text PDFPerspect Vasc Surg Endovasc Ther
September 2007
Carotid artery stenting (CAS) has emerged as a useful and potentially less invasive alternative to carotid endarterectomy (CEA) for the treatment of extracranial carotid stenoses. In this regard, it has been suggested that specific patient subgroups who may benefit from CAS including those with significant medical comorbidities, recurrent stenosis, anatomically inaccessible lesions, and a hostile neck. However, the purpose of this report is to evaluate whether or not CAS should replace CEA in the treatment of symptomatic and asymptomatic disease in better risk patients, also.
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