Browsing by Author "Miller, Chris"

Now showing 1 - 3 of 3
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    Inhaled nitric oxide as adjunctive therapy for severe malaria: a randomized controlled trial
    (BioMed Central, 2015-10-29) Hawkes, Michael T.; Conroy, Andrea L.; Opoka, Robert O.; Hermann, Laura; Thorpe, Kevin E.; McDonald, Chloe; Kim, Hani; Higgins, Sarah; Namasopo, Sophie; John, Chandy; Miller, Chris; Liles, W. Conrad; Kain, Kevin C.; Department of Pediatrics, School of Medicine
    Background Severe malaria remains a major cause of childhood mortality globally. Decreased endothelial nitric oxide is associated with severe and fatal malaria. The hypothesis was that adjunctive inhaled nitric oxide (iNO) would improve outcomes in African children with severe malaria. Methods A randomized, blinded, placebo-controlled trial of iNO at 80 ppm by non-rebreather mask versus room air placebo as adjunctive treatment to artesunate in children with severe malaria was conducted. The primary outcome was the longitudinal course of angiopoietin-2 (Ang-2), an endothelial biomarker of malaria severity and clinical outcome. Results One hundred and eighty children were enrolled; 88 were assigned to iNO and 92 to placebo (all received IV artesunate). Ang-2 levels measured over the first 72 h of hospitalization were not significantly different between groups. The mortality at 48 h was similar between groups [6/87 (6.9 %) in the iNO group vs 8/92 (8.7 %) in the placebo group; OR 0.78, 95 % CI 0.26–2.3; p = 0.65]. Clinical recovery times and parasite clearance kinetics were similar (p > 0.05). Methaemoglobinaemia >7 % occurred in 25 % of patients receiving iNO and resolved without sequelae. The incidence of neurologic deficits (<14 days), acute kidney injury, hypoglycaemia, anaemia, and haemoglobinuria was similar between groups (p > 0.05). Conclusions iNO at 80 ppm administered by non-rebreather mask was safe but did not affect circulating levels of Ang-2. Alternative methods of enhancing endothelial NO bioavailability may be necessary to achieve a biological effect and improve clinical outcome.
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    Relative Orthodontic Bracket Bond Strength Measured in Three Testing Modalities
    (1998) Harper, Oliver Seriki; Katona, Thomas R.; Baldwin, James J.; Hohlt, William F.; Shanks, James C.; Miller, Chris
    This project represents a continuation of work in which computer models, primarily FEM (Finite Element Model) stress analyses, and associated experiments, have been conducted to compare the strength measurement results obtained with three testing modalities (tension, shear-peel and torque). Simply stated, we have examined the following question: If a manufacturer, using tensile debonding loads, claims that product Y is twice as strong as product X, will the same results be obtained by a laboratory that used shear-peel or torsion testing? Madding tested three types of orthodontic bracket cements (System 1 +, a chemically cured resin (Res); Ketac-Fil, a self-cured glass ionomer (CC), and PhotacBond, a light-cured glass ionomer (LC)) in three loading modalities: tension, shear-peel, and torsion. Contrary to expectations, the results demonstrated that the relative bond strengths of the orthodontic cements were independent of the loading methods. One of the variables that may have contributed to these contradictory results is adhesive thickness. The aim of this study is to measure the relative bond strengths of three types of cements while maintaining the same adhesive thicknesses. Hypothesis: The relative bond strengths of three cements will be the same, regardless of the testing modality, if the bond thicknesses are held constant. Three commercially available systems were utilized: System 1 + (Res), Ketac-Fil (CC), and Photac-Bond (LC). One hundred and sixty two standard twin edgewise central incisor brackets were flattened with approximately 200 N per bracket using self-centering plates on an MTS Bionix machine. A total of 54 bovine incisor teeth were randomly divided into three groups (A, B, C). Each group of 18 teeth was bonded and rebounded with a single cement, and further divided into three subgroups of 6 (Al, A2, A3). Each specimen within all subgroups was initially "virgin" and subsequently recycled between different testing modalities (tensile, shear-peel and torque). A special bonding jig aided bracket placement and ensured parallelism between bracket base and enamel surface, while the thickness of the cement was held at 0. 152 mm. The debonding procedure in all three testing modalities was done on an MTS Bionix machine. The Adhesive Remnant Index (ARI) was determined stereomicroscopically for each specimen post debond. The trend of the results indicate that the relative bond strengths in tension and torsion was LC> Res> CC, whereas in shear-peel, Res> LC> CC. These results are contrary to the hypothesis and are significant for CC and LC, and between CC and Res in all testing modalities. There was only a weak correlation between ARI and bond strength for LC (r value= 0.59) and CC (r value= -0.48) in the shear-peel testing modality. Additionally, a weak correlation was found for LC (r value= 0.54) in the torsional testing modality. There were no correlations between bond strength and ARI for any of the three adhesives in the other testing modalities. Statistically, testing in torsion gave LC> Res> CC, but shear-peel and tension showed LC= Res> CC. In practical terms, the manufacturer of LC could legitimately claim that its product is stronger than Res. However, that torsion-based claim could not be made based on tension. Conclusion: The relative bond strengths of the three orthodontic cements are different and are influenced by the testing modality when the bond thickness is held constant.
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    Transient Bacteremia in Patients During the Orthodontic Banding Procedure
    (1976) Macri, James V.; Miller, Chris; Barton, Paul; Dirlam, James; Shanks, James
    The purpose of this investigation was to determine if the fitting and placement of orthodontic bands on patients induced a transient bacteremia. Twenty patients were included, and a total of 12 teeth were banded in each patient. Before any procedure was performed, a preoperative blood sample was taken. Three additional blood samples were taken throughout the procedure 30 to 90 seconds after visible hemorrhage occurred from the placement of the bands. The blood cultures were then incubated for seven days. Cultures that became dark after seven days were subcultured and incubated for 24 hours anaerobically and 24 hours aerobically in an attempt to detect the presence of bacteria. Of the 80 blood cultures taken during this study, only one preoperative blood sample became positive. However, the fact that no bacteremia was detected during the banding procedures does not conclusively exclude its presence. Until more work is done to show conclusively that a bacteremia does not occur during the banding procedure it would be advisable to follow the suggestion of the American Heart Association and prophylactically premedicate patients who are susceptible to SBE with antibiotics for those procedures that may cause hemorrhage.