Publications by authors named "Hazzard J"

Background: A sport-related concussion (SRC) is a common injury that affects multiple clinical domains such as cognition, balance, and nonspecific neurobehavioral symptoms. Although multidimensional clinical assessments of concussion are widely accepted, there remain limited empirical data on the nature and clinical utility of distinct clinical profiles identified by multimodal assessments.

Purpose: Our objectives were to (1) identify distinct clinical profiles discernible from acute postinjury scores on the Sport Concussion Assessment Tool (SCAT), composed of a symptom checklist, a cognitive assessment (Standardized Assessment of Concussion), and a balance assessment (Balance Error Scoring System), and (2) evaluate the clinical utility of the identified profiles by examining their association with injury characteristics, neuropsychological outcomes, and clinical management-related outcomes.

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Background: The prevalence of unreported concussions is high, and undiagnosed concussions can lead to worse postconcussion outcomes. It is not clear how those with a history of undiagnosed concussion perform on subsequent standard concussion baseline assessments.

Purpose: To determine if previous concussion diagnosis status was associated with outcomes on the standard baseline concussion assessment battery.

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Context: Preseason testing can be time intensive and cost prohibitive. Therefore, using normative data for postconcussion interpretation in lieu of preseason testing is desirable.

Objective: To establish the recovery trajectory for clinical reaction time (RTclin) and assess the usefulness of changes from baseline (comparison of postconcussion scores with individual baseline scores) and norm-based cutoff scores (comparison of postconcussion scores with a normative mean) for identifying impairments postconcussion.

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Context: Pre-season testing is often used to establish baseline scores for post-concussion interpretation. However, pre-season testing can be time-intensive and cost-prohibitive, in which case normative data may be used for post-injury interpretation.

Objective: To compare change from baseline and normative-based cutoff scores in interpreting clinical reaction time (RTclin) following concussion.

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Interferons are secretory proteins induced in response to specific extracellular stimuli which stimulate intra- and intercellular networks for regulating innate and acquired immunity, resistance to viral infections, and normal and tumor cell survival and death. Type 1 interferons plays a major role in the CD8 T-cell response to viral infection. The genomic analysis carried out here for type I interferons within Bovidae family shows that cattle, bison, water buffalo, goat, and sheep (all Bovidae), have different number of genes of the different subtypes, with a large increase in the numbers, compared to human and mouse genomes.

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Objective: To examine the association between estimated age at first exposure (eAFE) to American football and clinical measures throughout recovery following concussion.

Methods: Participants were recruited across 30 colleges and universities as part of the National Collegiate Athletic Association (NCAA)-Department of Defense Concussion Assessment, Research and Education Consortium. There were 294 NCAA American football players (age 19 ± 1 years) evaluated 24-48 hours following concussion with valid baseline data and 327 (age 19 ± 1 years) evaluated at the time they were asymptomatic with valid baseline data.

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Background: Identifying separate dimensions of concussion symptoms may inform a precision medicine approach to treatment. It was previously reported that a bifactor model identified distinct acute postconcussion symptom dimensions.

Purpose: To replicate previous findings of a bifactor structure of concussion symptoms in the Concussion Assessment Research and Education (CARE) Consortium sample, examine measurement invariance from pre- to postinjury, and evaluate whether factors are associated with other clinical and biomarker measures.

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Introduction: The purpose of this study was to calculate heritability estimates of alveolar bone thickness around maxillary and mandibular incisors.

Methods: The sample consisted of cone-beam computed tomography scans of 69 groups of siblings. The scans were analyzed, and Invivo5 software was used to measure the labial and lingual bone thickness.

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Context: In the absence of baseline testing, normative data may be used to interpret postconcussion scores on the clinical reaction-time test (RTclin). However, to provide normative data, we must understand the performance factors associated with baseline testing.

Objective: To explore performance factors associated with baseline RTclin from among candidate variables representing demographics, medical and concussion history, self-reported symptoms, sleep, and sport-related features.

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Background: Organizations recommend that athletes should be asymptomatic or symptom-limited before initiating a graduated return-to-play (GRTP) protocol after sports-related concussion, although asymptomatic or symptom-limited is not well-defined.

Hypotheses: (1) There will be a range (ie, beyond zero as indicator of "symptom-free") in symptom severity endorsement when athletes are deemed ready to initiate a GRTP protocol. (2) Baseline symptom severity scores and demographic/preinjury medical history factors influence symptom severity scores at the commencement of the GRTP protocol.

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Unlabelled: This systematic review and meta-analysis is to provide comprehensive evidence-based exercise recommendations targeting walking function for adults with Parkinson's disease.

Methods: Fixed- or random-effect meta-analyses estimated standardized effect sizes (Hedge's g), comparing treatment effects from exercise with nonexercise and another form of exercise (non-EXE control and EXE control). Cuing and exercise duration were used as moderators for subanalyses.

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Genetic polymorphisms and diversity of are essential because of gene's function in innate immunity and its association with infectious diseases resistance or tolerance in cattle. The present study was aimed at assessing the level of genetic diversity of DRB3 in the exon 2 (BoLA-DRB3.2) region in African, American and Asian cattle breeds.

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Objective: (1) To examine the prevalence of college-aged students on campus who had a history of concussion(s) or traumatic brain injury (TBI) and associated symptoms and (2) to evaluate the rate of campus service utilization among students who had a TBI.

Setting: A representative sampling, randomly selected campus-wide e-mail was sent out with a Qualtrics online survey.

Participants: College-aged students (N = 466, n = 429) at a northeastern US university responded and consented to participate in the online survey.

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Background: A student-athlete's mental state, including history of trait anxiety and depression, or current psychological state may affect baseline concussion assessment performance.

Purpose: (1) To determine if mental illness (anxiety, depression, anxiety with depression) influences baseline scores, (2) to determine if psychological state correlates with baseline performance, and (3) to determine if history of concussion affects Brief Symptom Inventory-18 (BSI-18) subscores of state anxiety, depression, and somatization.

Study Design: Cross-sectional study; Level of evidence, 3.

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Using health information technology (IT) can potentially address health disparities by increasing access to care, delivering higher-quality care, improving patient-provider communication, and enhancing patient safety. It describes challenges encountered by three underserved Beacon Communities that implemented health IT interventions, including inadequate connectivity infrastructure, technical support, expertise, and financial resources; provider shortages and staff turnover; and equipment theft.

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Whether the setting is urban, rural, or somewhere in between, engagement strategies for the underserved require a great deal of flexibility and sensitivity to the socioeconomic, cultural, and geographic conditions of the patient population. The following report details how three unique communities designed specific strategies to engage underserved populations in the management of their chronic conditions.

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Soluble guanylyl/guanylate cyclase (sGC), a heme-containing heterodimeric protein of approximately 150 kDa, is the primary receptor for nitric oxide, an endogenous molecule of immense physiological importance to animals. Recent studies have identified compounds such as YC-1 and BAY 41-2272 that stimulate sGC independently of NO binding, properties of importance for the treatment of endothelial dysfunction and other diseases linked to malfunctioning NO signaling pathways. We have developed a novel expression system for sGC from Manduca sexta (the tobacco hornworm) that retains the N-terminal two-thirds of both subunits, including heme, but is missing the catalytic domain.

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Article Synopsis
  • Intraprotein electron transfer (IET) from FMN to heme is crucial for NO synthesis in NO synthase, with previous studies focusing on a murine model.
  • Recent research presents IET kinetics in human and murine iNOS holoenzymes, revealing rate constants around 34-35 s(-1) for both, which are significantly slower than in truncated constructs.
  • The slower rates suggest a limiting step in the IET process due to the stability of the electron-accepting state, while the similarity to CaM-bound neuronal NOS indicates the activation by CaM reduces regulatory obstacles in the enzyme's function.
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Comparative CO photolysis kinetics studies on wild-type and autoregulatory (AR) insert-deletion mutant of rat nNOS holoenzyme were conducted to directly investigate the role of the unique AR insert in the catalytically significant FMN-heme intraprotein electron transfer (IET). Although the amplitude of the IET kinetic traces was decreased two- to three-fold, the AR deletion did not change the rate constant for the calmodulin-controlled IET. This suggests that the rate-limiting conversion of the electron-accepting state to a new electron-donating (output) state does not involve interactions with the AR insert, but that AR may stabilize the output state once it is formed.

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Intraprotein interdomain electron transfer (IET) from flavin mononucleotide (FMN) to heme is essential in nitric oxide (NO) synthesis by NO synthase (NOS). Our previous laser flash photolysis studies have provided a direct determination of the kinetics of IET between the FMN and heme domains in truncated oxyFMN constructs of rat neuronal NOS (nNOS) and murine inducible NOS (iNOS), in which only the oxygenase and FMN domains along with the calmodulin (CaM) binding site are present [Feng, C. J.

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Mutations G473D and A208D were identified in patients with isolated sulfite oxidase (SO) deficiency, and the equivalent amino acids (G451 and A186, respectively) have been localized to the vicinity of the molybdopterin active site in the X-ray structure of chicken SO [Kisker, C., Schindelin, H., Pacheco, A.

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Article Synopsis
  • Intramolecular electron transfer in zucchini squash ascorbate oxidase is inhibited by Ag(+) at equimolar concentrations, affecting the enzyme's activity.
  • At pH 5.5, the enzyme is initially reduced at a high rate by a generated semiquinone, followed by a slower equilibration of the reducing equivalent to the trinuclear copper cluster.
  • The presence of Ag(+) slows the return of the reducing equivalent to the Type I copper, leading to a decrease in the overall midpoint potential of the copper cluster and inhibiting enzyme activity.
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Purpose: Computerized tomography (CT) with 3-dimensional (3-D) reconstruction has gained acceptance as an imaging study to evaluate living renal donors. We report our experience with this technique in 199 consecutive patients to validate its predictions of arterial anatomy and kidney volumes.

Materials And Methods: Between January 1997 and March 2002, 199 living donor nephrectomies were performed at our institution using an open technique.

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Arginine 160 in human sulfite oxidase (SO) is conserved in all SO species sequenced to date. Previous steady-state kinetic studies of the R160Q human SO mutant showed a remarkable decrease in k(cat)/K(m)(sulfite) of nearly 1000-fold, which suggests that Arg 160 in human SO makes an important contribution to the binding of sulfite near the molybdenum cofactor [Garrett, R. M.

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Tyrosine 343 in human sulfite oxidase (SO) is conserved in all SOs sequenced to date. Intramolecular electron transfer (IET) rates between reduced heme (Fe(II)) and oxidized molybdenum (Mo(VI)) in the recombinant wild-type and Y343F human SO were measured for the first time by flash photolysis. The IET rate in wild-type human SO at pH 7.

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