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PubMed2007

Effect of an evidence-based paediatric fever education program on emergency nurses' knowledge.

INTRODUCTION: This study examined the effect of an educational intervention of factual knowledge on emergency nurses' knowledge and clinical decisions related to paediatric fever. METHOD: A prospective pre-test/post-test design was used. Emergency nurses' factual knowledge was measured by parallel multiple choice questions and the intervention for the study was an educational intervention consisting of two tutorials. Pre-test data were collected in early June 2005 and post-test data were collected during August 2005. RESULTS: Thirty-one emergency nurses completed the pre and post-test multiple choice questions. Emergency nurses' knowledge increased following the tutorials. Pre-test score was positively correlated with knowledge acquisition. Self-reports of independent decisions related to fever management were influenced by experience, hours of employment, level of appointment, postgraduate qualifications and pre-test score. DISCUSSION: High levels of variability in knowledge and knowledge acquisition suggest a review of undergraduate and postgraduate curricula is warranted. Although this study identified associations between independent fever management decisions and participant characteristics, further research is pivotal to better understanding these relationships.

Adult↗
PubMed2000

A tool for quantifying hip flexor function during gait.

An index to measure the change in hip flexor function after hip surgery was developed in the Motion Analysis Laboratory at Gillette Children's Specialty Healthcare (GCSH). The hip flexor index (HFI) utilizes principal component analysis applied to five kinematic and kinetic variables collected during normal acquisition of gait data. A single index number is derived that describes accurately the overall hip function. Initial clinical validation was carried out using a data set of 23 normal controls and six patients with a diagnosis of cerebral palsy. The patients were all independent ambulators who had undergone orthopedic hip surgery. The controls were used to establish patterns of interdependency between selected gait parameters and form a basis for the index number. The HFI based surgical outcome was compared to the subjective rating of six clinicians. The clinicians were versed in gait analysis and were blinded to the HFI based outcome. The HFI measure of post-operative change in hip function was found to correspond well with the subjective clinical evaluation. A valid tool such as the HFI can be used to objectify clinical impressions of change in hip function, and can thereby assist researchers with statistical and outcome analysis of interdependent and redundant gait variables.

Biomechanical Phenomena↗
PubMed2003

Spatio-temporal image correlation (STIC): a new tool for the prenatal screening of congenital heart defects.

OBJECTIVE: To assess the feasibility and capability of STIC acquisition, performed by a general obstetrician performing antenatal ultrasound, to visualize fetal cardiac structures in women undergoing routine obstetric ultrasound examination, in order to obtain information to confirm normality of the fetal heart during intrauterine life. METHODS: This was a prospective study of one hundred fetuses with echocardiographically confirmed normal hearts and no extracardiac anomalies with gestational ages ranging between 18 and 37 weeks. A general obstetrician was invited to acquire the STIC volumes. The four-chamber view was obtained as a starting point. A standard 7.5-s acquisition time and 30 degrees angle of acquisition were used and the resulting STIC was stored for later offline analysis by a fetal echocardiologist. For each patient, the stored STIC data were first evaluated by sweeping from the initial acquisition plane, in the caudal direction and then cranially, zooming, slowing or stopping the cardiac motion to visualize views and structures. If a structure or view was rated as inadequate or not identifiable, a multiplanar three-dimensional (3D) examination of the STIC volume was taken in order to try to visualize it adequately. The rates obtained using just the STIC sweeps were compared independently, and then the 3D multiplanar study was added. RESULTS: STIC acquisition was possible in all cases. The mean time required for STIC acquisition was 7.5 min. A complete cardiac examination according to the set criteria was achieved in 94.2% (95% confidence interval (CI), 90-99) of cases. We obtained a 94.2% success rate of visualizing different structures and views of the fetal heart using the STIC sweep alone (95% CI, 90-99) and 96.2% adding 3D multiplanar examination (95% CI, 92-100). CONCLUSION: STIC acquisition of the fetal heart is feasible with high success rates in visualization of the principal connections. The STIC data acquired by a general obstetrician can subsequently be used by a fetal echocardiologist for prenatal confirmation of normal cardiac structure or exclusion of major cardiac malformations.

Echocardiography, Three-Dimensional↗
PubMed2001

Mariner-like transposases are widespread and diverse in flowering plants.

Complete and partial sequences of mariner-like elements (MLEs) have been reported for hundreds of species of animals, but only two have been identified in plants. On the basis of these two plant MLEs and several related sequences identified by database searches, plant-specific degenerate primers were derived and used to amplify a conserved region of MLE transposase genes from a variety of plant genomes. Positive products were obtained for 6 dicots and 31 monocots of 54 plant species tested. Phylogenetic analysis of 68 distinct MLE transposase sequences from 25 grass species is consistent with vertical transmission and rapid diversification of multiple lineages of transposases. Surprisingly, the evolution of MLEs in grasses was accompanied by repeated and independent acquisition of introns in a localized region of the transposase gene.

DNA-Binding Proteins↗
PubMed1984

A multidetector alpha spectroscopy analysis system.

This document describes the attributes of an alpha spectroscopy counting and analysis system called Low Level Pulse Height Analysis (LLPHA). It was developed for multi-sample alpha spectroscopy analysis. The LLPHA system is controlled by a MIK-11/2 microcomputer with 28K of memory and uses a double-density, dual floppy disk for data storage. Detectors are interfaced to the computer via CAMAC (Computer Automated Measurement and Control) equipment. The system simultaneously supports 32 active and independent surface-barrier alpha-particle detectors. It operates with the total collection rate of up to 300 counts/sec from all active detectors, using 128 channels per spectrum and a dynamic energy range of 1.4 MeV. The system is not limited, however, to these conditions. In addition to spectral acquisition, the system provides analysis functions which include peak identification, curve-smoothing, integration, linear and logarithmic scale graphics, and corrections for base-line shift, dead-time, and background counts. These functions can be implemented while other spectra are being collected. The LLPHA system represents a highly cost-effective means of acquiring alpha spectrometric data from a large number of samples simultaneously and with rapid data analysis capability.

Alpha Particles↗
PubMed1990

Predicting distant metastases in operable breast cancer patients.

Risk factors for distant metastases following mastectomy and axillary node dissection for breast cancer were analyzed in a review of 1022 women. From diagnosis until the end of the adjuvant treatment, six stages were identified that corresponded well to patient data acquisition. At each stage, a prognosis study based on the Cox model was carried out using all acquired information from the first stage. The results demonstrated that tumor size, nuclear pleomorphism, mitotic index, and nodal status at the top of axilla were stable independent risk factors in predicting metastasis-free survival (MFS). These analyses also revealed those factors that were significantly related to MFS at one or several stages and losing their significance at a subsequent stage. This was the case with clinical node status, age, and vascular tumor emboli. Other factors such as estrogen, progesterone, histologic grade, and clinical stage were never identified as independent factors at any stage. The four major stable risk factors were used to define a stratification of reference. The results demonstrated that the mere knowledge of clinical information such as tumor size, clinical node status, and age would enable 51% of the patients to be universally well classified according to that stratification. Knowledge of additional factors, such as nuclear pleomorphism and mitotic index, would bring the rate up to 61%, and then to 64% if supplementary information such as vascular tumor emboli were acquired. These percentages did not appear high enough to claim that the physician may make a reliable prognosis of operable breast cancer patients before acquiring information from the axillary node dissection. However, it was proven that there exist some subsets of patients with stable prognosis, i.e., subsets of patients who will belong permanently to the same risk group through the stages.

Adult↗
PubMed1995

Proton spectroscopic imaging of the human brain using phased array detectors.

Two and four-coil phased array detectors have been developed to increase the sensitivity of proton spectroscopic imaging of the human brain. These include a quadrature figure-8 coil for the study of the vertex, several arrays of 2-4 small overlapping (6-8 cm diameter) circular coils and a combination figure-8 coil plus circular coil. These were constructed in our laboratory and tested to assess their utility for brain spectroscopy. Methods for optimally combining the data from the independent receivers based on the analytical coil maps or measured signal to noise ratios (SNRs) of the data were investigated. High spatial resolution (0.2-0.4 cm3 voxel size) two- or three-dimensional chemical shift images of normal brain were obtained in 17-minute acquisitions. These spatial resolutions are comparable to those previously obtained with conventional small surface coils, but the specialized detectors allow this sensitivity to be achieved for a larger region or for previously inaccessible areas such as the top of the head. The coverage and SNR increases demonstrated are similar to those obtained in magnetic resonance phased array imaging.

Brain↗
PubMed2005

Critical contribution of nonlinear chromatography to the understanding of retention mechanism in reversed-phase liquid chromatography.

The retention of most compounds in RPLC proceeds through a combination of several independent mechanisms. We review a series of recent studies made on the behavior of several commercial C18-bonded stationary phases and of the complex, mixed retention mechanisms that were observed in RPLC. These studies are essentially based on the acquisition of adsorption isotherm data, on the modeling, and on the interpretation of these data. Because linear chromatography deals only with the initial slope of the global, overall, or apparent isotherm, it is unable fully to describe the complete adsorption mechanism. It cannot even afford clues as to the existence of several overlaid retention mechanisms. More specifically, it cannot account for the consequences of the surface heterogeneity of the packing material. The acquisition of equilibrium data in a wide concentration range is required for this purpose. Frontal analysis (FA) of selected probes gives data that can be modeled into equilibrium isotherms of these probes and that can also be used to calculate their adsorption or affinity energy distribution (AED). The combination of these data, the detailed study of the best constants of the isotherm model, the determination of the influence of experimental parameters (e.g., buffer pH and pI, temperature) on the isotherm constants provide important clues regarding the heterogeneity of the adsorbent surface and the main properties of the adsorption mechanisms. The comparison of similar data obtained for the adsorption of neutral and ionizable compounds, treated with the same approach, and the investigation of the influence on the thermodynamics of phase equilibrium of the experimental conditions (temperature, average pressure, mobile phase composition, nature of the organic modifier, and, for ionizable compounds, of the ionic strength, the nature, the concentration of the buffer, and its pH) brings further information. This review provides original conclusions regarding retention mechanisms in RPLC.

Adsorption↗
PubMed1996

Resistant enterococci: a prospective study of prevalence, incidence, and factors associated with colonization in a university hospital.

OBJECTIVE: To determine the prevalence of gastrointestinal tract colonization with antibiotic-resistant enterococci at ward entry and to study the incidence and risk factors for nosocomial acquisition of colonization with resistant enterococci. DESIGN: A prospective cohort study conducted between February 1 and March 15, 1993. METHODS: Rectal cultures were obtained within 24 hours of admission or transfer onto the study wards and repeated at weekly intervals and at the time of discharge. Patients harboring antibiotic-resistant enterococci at the time of admission or after admission were compared to patients who were not colonized with these organisms. Clinical and epidemiologic risk factors for colonization were abstracted prospectively by daily chart review. Following a univariate analysis of risk factors associated with colonization, a multivariate statistical analysis using three separate models was done. SETTING: A 1,125-bed, tertiary-care teaching hospital in North Carolina. PATIENTS: A total of 350 patients admitted to two general medical wards and the medical intensive care unit during the study period. RESULTS: Antibiotic-resistant enterococci were isolated from 52 patients: 19 were colonized at admission to the study, and 33 later acquired resistant strains. At the time of admission, 5.4% of the patients were colonized with ampicillin-resistant enterococci (ARE), including 1.1% that were colonized with vancomycin-resistant enterococci. Prior hospitalization was associated with colonization with ARE at admission (P = .01). Independent risk factors for nosocomial acquisition of ARE included treatment with more than three antibiotics, empiric use of antibiotics, use of third-generation cephalosporins, and the use of enteral tube feedings. Antibiotics used prophylactically were not associated with resistant enterococcal colonization. CONCLUSIONS: Our data help to elucidate the epidemiology of gastrointestinal tract colonization with resistant enterococci. We hypothesize that surveillance and control programs will be more likely to succeed if targeted at patients receiving more than three antibiotics, empiric antibiotics, and enteral tube feedings (Infect Control and Hosp Epidemiol 1996;17:36-41).

Ampicillin Resistance↗
PubMed2005

Articulation in early and late bilinguals' two languages: evidence from functional magnetic resonance imaging.

The network of cortical and subcortical regions that contribute to articulation was examined in bilinguals using functional magnetic resonance imaging. Participants were all fluent in French and English: half were bilingual from birth and half were 'late bilinguals' who had learned French after the age of 12. Overt articulation resulted in the bilateral activation of the motor cortex, basal ganglia and cerebellum, and also the supplementary motor area, independent of the language spoken. Furthermore, the threshold and extent of the network involved in articulation was identical for the two bilingual groups with the exception of greater variation in the left putamen for the late bilinguals. These data challenge claims that age of acquisition results in fundamental differences in the neural substrates that subserve language in bilinguals.

Adult↗
PubMed1991

Influence of different sources on the processing and biopharmaceutical properties of high-dose ibuprofen formulations.

It is known that depending on the manufacturing and synthetic processes, drugs may exist as different forms. As a result, physicochemical properties, compression characteristics, intrinsic dissolution and bioavailability may vary substantially. The purpose of this study was to investigate the effect of different sources of ibuprofen on the processing of tablets and on their properties. Another emphasis of this work was to rationalize one or several key characteristics of the raw material as directly related to wet granulation parameters and to the behavior of final tablets. Commercially available ibuprofen was obtained from different manufacturers and a preformulation program, including X-ray crystallography, differential scanning calorimetry, scanning electron microscopy, determination of particle size distribution and flowability, was performed to characterize the raw material. Granules were prepared with a planetary mixer and liquid requirements for the end point were obtained by monitoring power consumption. Tablets were manufactured on Stokes rotary and single punch instrumented presses. Data acquisition interfaces produced compression data for each formulation. Granules and final tablets were analyzed for hardness, dissolution profiles and content uniformity. Statistical evaluations using analysis of variance and multiple comparison procedures were performed on the results to determine the significance of the variability between independent parameters. The ibuprofen tested was found to be a unique polymorphic form with some differences in the external crystallinity. The particle size characteristics of the material also allowed a differentiation between sources and although there was no differences in dissolution patterns or content uniformity, particle size was found to account for 50% of the variability in tablet hardness. Two sources of ibuprofen with lower mean particle size showed significant variations in end point liquid requirements resulting in variable tablet crushing strength.

Biopharmaceutics↗
PubMed2001

The fusion of anatomic and physiologic imaging in the management of patients with cancer.

Imaging is of major clinical importance in the noninvasive evaluation and management of patients with cancer. Computed tomography (CT) and other anatomic imaging modalities, such as magnetic resonance imaging (MRI) or ultrasound, have a high diagnostic ability by visualizing lesion morphology and by providing the exact localization of malignant sites. Nuclear medicine provides information on the function and metabolism of cancer. Over the last decade, there have been numerous attempts to combine data obtained from different imaging techniques. Fused images of nuclear medicine and CT (or to a lesser extent, MRI) overcome the inherent limitations of both modalities. Valuable physiologic information benefits from a precise topographic localization. Coregistered data have been shown to be useful in the evaluation of patients with cancer at diagnosis and staging, in monitoring the response to treatment, and during follow up, for early detection of recurrence. Time-consuming and difficult realignment and computation for fusion of independent studies have, until now, limited the use of registration techniques to pilot studies performed in a small number of patients. The development of the new technology of single photon emission computed tomography/CT and positron emission tomography/CT that allows for combined functional and anatomic data acquisition has the potential to make fusion an everyday clinical tool.

Diagnostic Imaging↗
PubMedDate not supplied

Clinical impact of arrhythmias on gated SPECT cardiac myocardial perfusion and function assessment.

BACKGROUND: We reported previously that mean quantified cardiac functional parameters computed by one gated single photon emission computed tomography (SPECT) technique were not significantly altered by common gating errors. However, it is not known to what extent other gated SPECT approaches that are based on different ventricular modeling assumptions are influenced by arrhythmias, nor are the effects of gating errors on visual analyses and their subsequent clinical implications known. METHODS: Projection data for 50 patients (aged 64 +/- 12 years; 68% men; 76% with myocardial perfusion defects) undergoing technetium-99m sestamibi gated SPECT who were in sinus rhythm during data acquisition were altered to simulate common arrhythmias. To determine quantitative effects, we performed calculations for original control and altered images by Gaussian myocardial detection (Quantitative Gated SPECT [QGS] program) and by wall thickening derived from gated perfusion polar maps (Emory Cardiac Toolbox program). To evaluate visual assessment in control and simulated-arrhythmia tomograms, 2 experienced blinded observers independently interpreted perfusion from polar maps and wall motion and thickening from tomographic cines, using a 4-point scale. RESULTS: Although mean functional parameters were scarcely altered, paired t tests showed ejection fraction fluctuations to be significantly different from control values, causing patients to change between abnormal and normal ejection fraction categories (2% of patients by QGS and 14% by Emory Cardiac Toolbox). Visual examination of QGS polar perfusion and function maps showed changes for 72% of cases, although in only 4% were these considered to have potential clinical consequences. The kappa statistic for visual analysis of concordance between control and arrhythmia readings showed that agreement was "excellent" for perfusion, "good" for motion, and "marginal" for thickening. CONCLUSIONS: As with quantitative measurements, thickening is the parameter most prone to error in the presence of arrhythmias. It is important to test data for gating errors to avoid potentially erroneous measurements and visual readings.

Arrhythmias, Cardiac↗
PubMedDate not supplied

Operant GSR conditioning with cool air reinforcement.

Two groups of 20 Ss each run individually in a soundproff chamber heated to 115 F and humidified to 100%. Ss in the experimental group received brief presentation of cool air contingent upon wmitted GSRs during 20 min of acquisition. Control Ss were matched on at a time in operant rate and were yoked one at a time to receive the cool air on a response-independent schedule. Both groups increased significantly in rate of unelicited GSRs during acquisition, with the experimental Ss' curve rising more rapidly and both groups attaining equivalent terminal levels. During extinction, the groups maintained high levels of responding and did not differ. Examination of basal skin conductance data ruled our an activation hypothesis. In the control Ss, terminal response frequency was significantly correlated with percentage of fortuitous response-contigent reinforcement. It was concluded that both croups were conditioned, with the controls receiving intermittent reinforcement sufficiently often to elevate their responding. The cool air was judged to be an effective reinforcer of unelicited GSRs, perhaps more effective than those used in previous studies.

Air↗
PubMed2002

Standard gas addition: a calibration method for handling temporal drifts of mass spectrometry-based sensors.

This work describes a new method for the correction of signal drift of a MS-based sensor by standard gas addition (SGA). It consists of introducing a gaseous He-Xe mixture continuously and independently of the carrier gas into the mass spectrometer source. To mimic the disturbances generated by periodical tuning of the mass detector, three series of adjustments were made to the main acquisition parameters. The influence of the SGA signal correction on the discriminating power of the data was evaluated from the analysis of three batches of cheeses by dynamic headspace coupled to mass spectrometry. SGA afforded a good correction of the main types of drift classically observed in mass spectrometry.

Biosensing Techniques↗
PubMed1994

Reconstitution of an operational MHC class II compartment in nonantigen-presenting cells.

Professional antigen-presenting cells (APCs) have a distinct compartment in which class II molecules are proposed to acquire antigenic peptides. Genetic evidence suggests that human leukocyte antigen (HLA)-DM, an unusual class II molecule, participates in this process. Peptide acquisition was reconstituted in nonprofessional APCs by transfection of class II, invariant chain (li), and H-2M, the murine equivalent of DM. The H-2M heterodimer appeared in an endosomal compartment, not at the cell surface, and the localization was independent of li. The data presented show that H-2M, class II, and li are the minimally required components for efficient formation of stable class II-peptide complexes, and thus for a functional class II compartment.

Amino Acid Sequence↗
PubMed1991

[State-trait characteristics of various measured variables of psychophysiologic activation, cognitive performance and mood in common everyday situations].

The distinction between state and trait sources of variation in psychological variables, familiar in differential psychology ever since the work of Cattell, is translated into a linear model of state-trait analysis. On the basis of this model indices of relative state- and trait variance of a measure (independent of errors of measurement) and the psychometric reliability of the same measure (independent of true state variance) can be determined. The model is applied to a larger set of data from in-field research employing 149 male high-school students (average age 17 years) from the city of Hamburg. Following a time-sampling plan of data acquisition, subjects were requested over a period of three successive weeks and on the average twelve times a day to indicate (on a portable computerized behavioral data recorder) their current mood and feeling and had to answer short psychometric tests (in-field psychometrics); in addition, two peripheral psychophysiological measures of activation (heart rate, finger temperature) were recorded. The psychophysiological measures depended on state variations to about two thirds of their true score variance, the different cognitive tests to about 50 to 80 percent of their true score variance on trait variations. Different scales for recording current mood and feeling states gave different state-trait variance percentages. The method also allows for determining intraindividual psychometric state reliability coefficients. Fields of application of the method in different areas of psychology are indicated.

Adolescent↗
PubMed1997

Helical CT angiography of the thoracic aorta.

Five years after its introduction (11,36), spiral or helical CTA is being embraced as an important noninvasive tool for imaging the thoracic aorta and its branches. The high degree of accessibility and ease with which the studies are performed make it a viable alternative to aortography in the acute setting. Once the examiner is familiar with the principles of CTA, the acquisition phase of the examination can be completed in as little as 15 minutes, but it is critical that a thorough understanding of these principles guide the radiologist to maximize information gained by the technique. Several important challenges remain for CTA. First, the proliferation of image-processing workstations and software is improving our ability to exploit these CT data by allowing us to visualize them in novel ways (37) and create alternative renderings with greater ease and speed. Before relying on these alternative visualization techniques, their accuracy and pitfalls, and the incremental gain they achieve over interpretation of the primary transverse sections must be fully established. This requires that carefully designed studies with multiple blinded and independent reviewers isolate interpretative variations based on rendering technique alone, and not a combination of rendering and acquisition techniques where variables readily are confounded (38). Second, more investigators must step forward with results of the clinical utility of CTA to triage patients appropriately and direct medical and surgical therapy. Although well designed prospective comparisons of imaging examinations and measurement of patient outcomes are challenging to implement, they are critical to the rational selection of appropriate diagnostic tests. This is particularly true for the application of helical CTA to imaging of the posttraumatic aortic and aortic dissection. Finally, helical CT technology is far from static. Every year, new advances in engineering bring better image quality, improved resolution, and faster scan times. As medical imagers, we must not become complacent, but rather constantly challenge ourselves to consider how we might further improve on our use of CT equipment to maximize the collection of information relevant to diagnosis and therapy.

Aortic Dissection↗