Publications by authors named "Snell E"

The use of long-read direct RNA sequencing (DRS) and PCR cDNA sequencing (PCS) in clinical oncology remains limited, with no direct comparison between the two methods. We used DRS and PCS to study clear cell renal cell carcinoma (ccRCC), focusing on new transcript and gene discovery. Twelve primary ccRCC archival tumors, six from patients who went on to relapse, were analyzed.

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Musculoskeletal (MSK) pathology encompasses an array of conditions that can cause anything from mild discomfort to permanent injury. Their prevalence and impact on disability have sparked interest in more effective treatments, particularly within orthopedics. As a result, the human placenta has come into focus within regenerative medicine as a perinatal derivative (PnD).

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Diffraction-based structural methods contribute a large fraction of the biomolecular structural models available, providing a critical understanding of macromolecular architecture. These methods require crystallization of the target molecule, which remains a primary bottleneck in crystal-based structure determination. The National High-Throughput Crystallization Center at Hauptman-Woodward Medical Research Institute has focused on overcoming obstacles to crystallization through a combination of robotics-enabled high-throughput screening and advanced imaging to increase the success of finding crystallization conditions.

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Objective: This study was undertaken to describe clinical manifestations in patients with Th/To antibody-positive systemic sclerosis (SSc) during long-term follow-up.

Methods: We performed a case-control study involving anti-Th/To antibody-positive patients with SSc who were newly referred to the University of Pittsburgh Medical Center and the Pittsburgh Scleroderma Center from 1980 to 2015. For every case, 2 anti-Th/To antibody-negative SSc patients (the first 2 consecutively seen after a case) were used as controls.

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Understanding protein folding is crucial for protein sciences. The conformational spaces and energy landscapes of cold (unfolded) protein states, as well as the associated transitions, are hardly explored. Furthermore, it is not known how structure relates to the cooperativity of cold transitions, if cold and heat unfolded states are thermodynamically similar, and if cold states play important roles for protein function.

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X-ray-based techniques are a powerful tool in structural biology but the radiation-induced chemistry that results can be detrimental and may mask an accurate structural understanding. In the crystallographic case, cryocooling has been employed as a successful mitigation strategy but also has its limitations including the trapping of non-biological structural states. Crystallographic and solution studies performed at physiological temperatures can reveal otherwise hidden but relevant conformations, but are limited by their increased susceptibility to radiation damage.

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The COVID-19 pandemic has resulted in 198 million reported infections and more than 4 million deaths as of July 2021 (covid19.who.int).

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Many biological systems across scales of size and complexity exhibit a time-varying complex network structure that emerges and self-organizes as a result of interactions with the environment. Network interactions optimize some intrinsic cost functions that are unknown and involve for example energy efficiency, robustness, resilience, and frailty. A wide range of networks exist in biology, from gene regulatory networks important for organismal development, protein interaction networks that govern physiology and metabolism, and neural networks that store and convey information to networks of microbes that form microbiomes within hosts, animal contact networks that underlie social systems, and networks of populations on the landscape connected by migration.

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The global COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has wreaked unprecedented havoc on global society, in terms of a huge loss of life and burden of morbidity, economic upheaval and social disruption. Yet the sheer magnitude and uniqueness of this event has also spawned a massive mobilization of effort in the scientific community to investigate the virus, to develop therapeutics and vaccines, and to understand the public health impacts. Structural biology has been at the center of these efforts, and so it is advantageous to take an opportunity to reflect on the status of structural science vis-à-vis its role in the fight against COVID-19, to register the unprecedented response and to contemplate the role of structural biology in addressing future outbreak threats.

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A significant problem in biological X-ray crystallography is the radiation chemistry caused by the incident X-ray beam. This produces both global and site-specific damage. Site specific damage can misdirect the biological interpretation of the structural models produced.

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The purpose of this investigation was to observe laryngeal tissue and vocal function changes over the course of 28 days in a single participant diagnosed by a laryngologist with bilateral nodules. Laryngeal imaging, acoustic variables and perceptual assessments of voice quality, and perceived vocal effort were obtained every morning for 28 consecutive days. A daily journal of occupational and recreational voice use as well as menstruation and alcohol consumption was maintained each day.

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Purpose The purpose of this preliminary study was to identify a vocal task that could be used as a clinical indicator of the vocal aptitude or vocal fitness required for vocally demanding occupations in a manner similar to that of the anaerobic power tests commonly used in exercise science. Performance outcomes for vocal tasks that require rapid acceleration and high force production may be useful as an indirect indicator of muscle fiber complement and bioenergetic fitness of the larynx, an organ that is difficult to study directly. Method Sixteen women (age range: 19-24 years, = 22 years) were consented for participation and completed the following performance measures: forced vital capacity, three adapted vocal function tasks, and the horizontal sprint test.

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grows in highly antibiotic-tolerant biofilms during chronic airway infections. Dispersal of bacteria from biofilms may restore antibiotic susceptibility or improve host clearance. We describe models to study biofilm dispersal in the nutritionally complex environment of the human airway.

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Transforming growth factor β-1 (TGFβ-1) is a secreted signalling protein that directs many cellular processes and is an attractive target for the treatment of several diseases. The primary endogenous activity regulatory mechanism for TGFβ-1 is sequestration by its pro-peptide, latency-associated peptide (LAP), which sterically prohibits receptor binding by caging TGFβ-1. As such, recombinant LAP is promising as a protein-based therapeutic for modulating TGFβ-1 activity; however, the mechanism of binding is incompletely understood.

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Metalloproteins comprise over one-third of proteins, with approximately half of all enzymes requiring metal to function. Accurate identification of these metal atoms and their environment is a prerequisite to understanding biological mechanism. Using ion beam analysis through particle induced X-ray emission (PIXE), we have quantitatively identified the metal atoms in 30 previously structurally characterized proteins using minimal sample volume and a high-throughput approach.

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Dissociation of transforming growth factor beta-1 (TGFβ-1) from the inhibitory protein latency-associated peptide (LAP) can occur from low doses of X-ray irradiation of the LAP-TGFβ-1 complex, resulting in the activation of TGFβ-1, and can have health-related consequences. Using the tools and knowledge developed in the study of radiation damage in the crystallographic setting, small-angle X-ray scattering (SAXS) and complementary techniques suggest an activation process that is initiated but not driven by the initial X-ray exposure. LAP is revealed to be extended when not bound to TGFβ-1 and has a different structural conformation compared to the bound state.

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Xylose isomerase (XI) is an industrially important metalloprotein studied for decades. Its reaction mechanism has been postulated to involve movement of the catalytic metal cofactor to several different conformations. Here, a dose-dependent approach was used to investigate the radiation damage effects on XI and their potential influence on the reaction mechanism interpreted from the X-ray derived structures.

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Protein structural vibrations impact biology by steering the structure to functional intermediate states; enhancing tunneling events; and optimizing energy transfer. Strong water absorption and a broad continuous vibrational density of states have prevented optical identification of these vibrations. Recently spectroscopic signatures that change with functional state were measured using anisotropic terahertz microscopy.

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Objective: The purpose of the study was to test the ability of oculomotor, vestibular, and reaction time (OVRT) metrics to serve as a concussion assessment or diagnostic tool for general clinical use.

Setting And Participants: Patients with concussion were high school-aged athletes clinically diagnosed in a hospital setting with a sports-related concussion (n = 50). Control subjects were previously recruited male and female high school student athletes from 3 local high schools (n = 170).

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The Machine Recognition of Crystallization Outcomes (MARCO) initiative has assembled roughly half a million annotated images of macromolecular crystallization experiments from various sources and setups. Here, state-of-the-art machine learning algorithms are trained and tested on different parts of this data set. We find that more than 94% of the test images can be correctly labeled, irrespective of their experimental origin.

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Sequencing the RNA in a biological sample can unlock a wealth of information, including the identity of bacteria and viruses, the nuances of alternative splicing or the transcriptional state of organisms. However, current methods have limitations due to short read lengths and reverse transcription or amplification biases. Here we demonstrate nanopore direct RNA-seq, a highly parallel, real-time, single-molecule method that circumvents reverse transcription or amplification steps.

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Article Synopsis
  • Serial femtosecond crystallography relies on efficient delivery of fresh crystals to an X-ray free-electron laser during experiments.
  • A new double-flow focusing nozzle has been developed that reduces sample consumption and enhances jet stability compared to earlier models.
  • This nozzle successfully determined the first room-temperature structure of RNA polymerase II and was tested on other protein samples, including an extradiol ring-cleaving dioxygenase.
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Nearly all protein functions require structural change, such as enzymes clamping onto substrates, and ion channels opening and closing. These motions are a target for possible new therapies; however, the control mechanisms are under debate. Calculations have indicated protein vibrations enable structural change.

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