Publications by authors named "Burleson D"

Many stool-based gut microbiome studies have highlighted the importance of the microbiome. However, we hypothesized that stool is a poor proxy for the inner-colonic microbiome and that studying stool samples may be inadequate to capture the true inner-colonic microbiome. To test this hypothesis, we conducted prospective clinical studies with up to 20 patients undergoing an FDA-cleared gravity-fed colonic lavage without oral purgative pre-consumption.

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Background: Colonoscopies provide a crucial diagnostic and surveillance tool for inflammatory bowel disease (IBD). Accordingly, IBD patients undergo repeated and frequent colonoscopies. The oral purgative bowel prep (BP) is often burdensome on patients, resulting in delayed or missed colonoscopies due to patient noncompliance.

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Hurricanes can cause widespread environmental pollution that has yet to be fully articulated. This study develops a predictive water quality model to forecast potential contamination resulting from buckled or ruptured storage tanks in coastal industrialized areas when subjected to storm surge. The developed EFDC-Storm Surge model (EFDC-SS) couples EPA's EFDC code with the SWAN-ADCIRC hurricane simulation model.

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A software system, SPATS (patent pending), that tests and trains important bottom-up and combined bottom-up/top-down speech-perception skills is described. Bottom-up skills are the abilities to identify the constituents of syllables: onsets, nuclei, and codas in quiet and noise as produced by eight talkers. Top-down skills are the abilities to use knowledge of linguistic context to identify words in spoken sentences.

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Goethite (alpha-FeOOH) is an antiferromagnetic iron oxyhydroxide that is often synthesized by precipitation from homogeneous, aqueous solution followed by aging. This paper addresses goethite growth by phase transformation of six-line ferrihydrite nanoparticles to goethite followed by oriented aggregation of the goethite primary particles. Data tracking goethite nanocrystal growth as a function of pH, temperature, and time is presented.

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On the characterization of environmental nanoparticles.

J Environ Sci Health A Tox Hazard Subst Environ Eng

January 2005

The presence and release of nanoparticles into the environment has important implications for human health and the environment. This article highlights and describes techniques that are effective in the characterization of anthropogenic and naturally occurring nanoparticles. Particle attributes like size, size distribution, shape, structure, microstructure, composition, and homogeneity are critically important to determining the potential impact of such materials on health and the environment.

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Objectives: To study perceptions of physicians and nursing staff about real-time demands and capacity of an emergency department (ED). To use ED data to calculate proposed demand ratios called Real-time Emergency Analysis of Demand Indicators (READI) scores. To compare the READI scores with ED staff perceptions of demand and capacity.

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In an earlier neonatal porcine model of smoke inhalation injury (SII), immediate postinjury application of partial liquid ventilation (PLV) had dramatic beneficial effects on lung compliance, oxygenation, and survival over a 24-h period. To explore the efficacy of PLV following SII, we treated animals at 2 and 6 h after SII and followed them for 72 h. Pigs weighing 8-12 kg were sedated and pharmacologically paralyzed, given a SII, and placed on volume-cycled, pressure-limited ventilation.

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Patients with posterior burns require extensive stays in the intensive care unit for recovery. The authors hypothesized that pulsating low-air-loss therapy would decrease the intensive care unit length of stay for burn patients, resulting in a potentially significant reduction in charges to payors. Eighty-one posterior burn patients enrolled in the primary study were randomly assigned to a pulsating low-air-loss surface (study group) or a nonpulsating low-air-loss surface (control group).

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Isolated human PMNs served as a model to determine oxyhemoglobin (oxyHb) binding and the effects of oxymyoglobin (oxyMb) or oxyHb on production of both nitric oxide (NO*) and superoxide (O2*-) and the resulting cytotoxicity. Physiologically relevant concentrations of NO* and H2O2 oxidized, to a similar extent, 2,7-dichlorodihydrofluorescein (DCFH) loaded into polymorphonuclear neutrophils (PMNs). Activation of PMNs with phorbol 12-myristate 13-acetate (PMA) markedly increased the internalization of extracellular oxyHb (10-250 microg/mL).

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Nitrate analysis in body fluids is an important part of the study of nitric oxide metabolism. A sensitive, simple procedure for nitrate analysis was developed by producing nitrobenzene from the nitrate in the samples and benzene. The nitrobenzene produced was measured on a gas chromatograph (GC) equipped with a nitrogen-phosphorous detector.

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In a random sample of 20 hospitals, the availability and consistency of five patient outcome indicators were examined, including medication administration errors, patient falls, occurrence of new decubitus ulcers, nosocomial infections, and unplanned readmission to the hospital. The results indicate that information about only two outcome indicators--medication errors and patient falls--were collected consistently by the sampled hospitals. The findings are discussed in the context of implications for the study of patient outcomes research.

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Injury elicits a response from all cells of the immune system in which cytokines and other metabolic products of activated leukocytes can act either beneficially to provide for enhanced host resistance or deleteriously to depress the function of remote organs and cause what has been termed systemic inflammation. These at times antithecal responses of leukocytes that appear to integrate postinjury changes in the neuroendocrine, immune, and coagulation systems have been implicated as principal causative factors in multiple systems organ failure. Numerous investigators have evaluated a variety of therapeutic agents to prevent and control infection by restoring leukocyte function, while others have evaluated antagonists and monoclonal antibodies as a means of controlling the exaggerated and persistent actions of leukocytes and cytokines caused by systemic inflammation.

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We measured plasma levels of interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF alpha), and interleukin-6 (IL-6) following thermal injury. Cytokine levels in the plasma of 27 burned patients were serially screened by ELISA and compared with cytokine levels in 16 healthy laboratory employees. The relationships between cytokine concentrations and patient mortality, burn size, and time postburn were examined.

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Objective: The relationship of plasma cytokine levels to infection, core temperature, and to one another in patients with thermal injury was examined.

Summary Background Data: The response to infection has been associated with cytokines such as interleukin 1 beta (IL1 beta), interleukin 6 (IL6), and tumor necrosis factor alpha (TNF alpha), and these cytokines have been studied in various inflammatory diseases. The authors previously reported that patients with thermal injury have elevated IL1 beta and IL6 plasma levels and that these cytokines may play different roles in the response to thermal injury.

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Background: Alterations in granulocyte function after thermal injury have been described. We have serially studied the level of granulocyte cytosolic peroxidase activity in 23 thermally injured patients during the first 6 weeks after injury. The patients' mean age and burn size were 35.

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Several fluorescent substances are present in the supernatants of acid-precipitated whole blood or plasma from burned patients. Perchloric acid supernatants of sera from infected, but not uninfected, burned rats contained a fluorescent substance with maximum emission at 420 nm at 355-nm excitation (355 ex/420 em). In this study of serum from burned human patients, several fluorescent substances were resolved by reverse-phase high-pressure liquid chromatography.

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Clinical and animal studies suggest that burn injury induces alterations in zinc metabolism. It also has been established that zinc nutriture can cause alterations in the immune response, but there is a paucity of information concerning the interrelationship between burn injury, zinc nutriture and the immune response. In the present study, rats were subjected to full skin thickness dorsal scald injuries covering 30 per cent of the total body surface and then maintained on sufficient or deficient zinc intake.

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The effect of blood transfusions and anesthesia on host response to endotoxin was evaluated in multiple Lewis rat models. The rats were randomized to receive A'Sogaloff Cancer Institute rat blood, pentobarbital sodium, or lactated Ringer's solution and, at either 2 or 7 days following administration of these agents, were challenged with intravenous endotoxin. Neither blood transfusions nor anesthesia altered mortality when administered 2 days before endotoxin challenge.

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We studied the effects of granulocyte-macrophage colony-stimulating factor in burn patients. Serial measurements of granulocyte oxidative function were obtained in treated patients and in a group of controls matched for age and total burn size. The administration of granulocyte-macrophage colony-stimulating factor resulted in a 50% increase in mean leukocyte counts.

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Transfusions are reported to increase the incidence of tumor metastasis in clinical studies and primary tumor growth in animal studies. We evaluated the effect of transfusions on immunologic response to primary and metastatic tumors in multiple rat models. One half of the animals were administered lactated Ringer's solution and one half ACI rat blood at the time of tumor challenge.

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Burn injuries have been shown to impair immune function. One of the hypotheses for the etiology of the immunosuppression is that burn injuries result in an elevation of prostaglandin E (PGE) levels which then impair leukocyte function. We evaluated the effect of PGE levels on immune function in multiple animal models utilizing T cell subset levels for our immunologic measurements.

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The effects of prophylactic administration of intravenous IgG on immune-cell phenotype and function in burn patients were compared with those of patients receiving standard therapy. Intravenous IgG infusions were given twice weekly for three weeks postburn or until wound closure. Intravenous IgG had no effect on the proportion of total T-lymphocytes, T-helper lymphocytes, or T-suppressor lymphocytes, but the proportion of B-lymphocytes decreased 40% in treated patient samples.

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