Search results for "Reproducibility"
showing 10 items of 1976 documents
An exploratory study of two Caco-2 cell models for oral absorption: A report on their within-laboratory and between-laboratory variability, and their…
2010
In 2005, the European Centre for the Validation of Alternative Methods (ECVAM) sponsored a study aimed at evaluating the reproducibility (between-laboratory and within-laboratory variability) and the predictive capacity of two in vitro cellular systems — the Caco-2/ATCC parental cell line and the Caco-2/TC7 clone — for estimating the oral fraction absorbed (Fa) in humans. Two laboratories, both of which had experience with Caco-2 cultures, participated in the study. Ten test chemicals with documented in vivo oral absorption data were selected. Atenolol, cimetidine and propranolol were included as reference compounds for low, medium and high intestinal absorption, respectively. Transport ex…
Interobserver discrepancy in liver fibrosis using transient elastography
2012
Summary. Transient elastography is a useful method to assess liver fibrosis, but uncertainties still exist regarding reliability and reproducibility of the technique. We aimed to improve knowledge on interobserver variability with the procedure and tried to find factors associated with such variability. This was a cross-sectional study to compare the results of transient elastography performed by two different operators, one test made just after the other. We assessed both results with correlation tests and with repeated parametric or nonparametric tests, as needed. We also carried out a multivariate analysis to find factors associated with discrepancy in the results obtained by the two op…
Systematic analysis of esophageal pressure topography in high-resolution manometry of 68 normal volunteers
2013
Summary The introduction of high-resolution manometry (HRM) has been a significant advance in esophageal diagnostics. Normative values however are currently based upon a single set of published reference values, and multiple new metrics have been added over the past several years. Our goal was to provide a second set of ‘normal-values’ and to include all current metrics suggested by the 2012 Chicago classification. Sixty-eight subjects without foregut symptoms or previous surgery (median age 25.5 years, ranging from 20–58 years, 53% female) underwent esophageal motility assessment via an established standardized protocol. Normative thresholds were calculated for esophago-gastric junction (E…
Quantitative Tissue Doppler Echocardiography: Physiological Nonuniformity of Left Ventricular Transmural Myocardial Wall-Motion Velocities and Gradie…
2001
Tissue Doppler echocardiography (TDE) is a new method by which transmural myocardial function can be studied noninvasively. In order to investigate physiology and reproducibility, 24 young, healthy volunteers were examined by M-mode TDE. Nonuniformity of transmural tissue layer velocities became apparent: Subendocardial and subepicardial velocities of the anteroseptal myocardial wall (AW) were 3.5 +/- 0.7 and 1.3 +/- 0.5 cm/sec (P < 0.0001, t-test), whereas in the posterolateral wall (PW) values of 3.6 +/- 0.6 and 1.2 +/- 0.4 cm/sec (P < 0.0001, t-test), respectively, were revealed. The ratios, termed "myocardial velocity gradients" as a new indicator of left ventricular performance, were 3…
Computerized estimation of quality standards for the X-ray densitometric assessment of myocardial perfusion
2003
The densitometric evaluation of heart-phase-gated digital subtraction coronary angiograms derives different parameters which provide information about coronary blood flow, myocardial perfusion, and coronary flow reserve: appearance time, rise time, mean ascending time, and maximum intensity. The reliability and reproducibility of these measurements and of the derived parameters were investigated. Four digital subtraction coronary angiograms were obtained in ten patients, including two baseline measurements and two measurements under hyperemia induced by papaverine ic. Different reproducibility results were found for the parameters, depending on the heart phase of the densogram (diastolic be…
Reliability of isokinetic assessment of shoulder-rotator strength: a systematic review of the effect of position.
2011
Context:Isokinetic assessment of shoulder internal- (IR) and external-rotator (ER) strength is commonly used with many different postures (sitting, standing, or supine) and shoulder positions (frontal or scapular plane with 45° or 90° of abduction).Objective:To conduct a systematic review to determine the influence of position on the intersession reliability of the assessment of IR and ER isokinetic strength, to identify the most reliable position, and to determine which isokinetic variable appears to be most stable in intersession reliability.Evidence Acquisition:A systematic literature search through MEDLINE and Pascal Biomed databases was performed in October 2009. Criteria for inclusion…
The accuracy of calculated base excess in blood.
2002
Most equations used for calculation of the base excess (BE, mmol/l) in human blood are based on the fundamental equation derived by Siggaard-Andersen and called the Van Slyke equation: BE = Z x [[cHCO3-(P) - C7.4 HCO3-(P)] + beta x (pH -7.4)]. In simple approximation, where Z is a constant which depends only on total hemoglobin concentration (cHb, g/dl) in blood, three equations were tested: the ones proposed by Siggaard-Andersen (SA), the National Committee for Clinical Laboratory Standards (NCCLS) or Zander (ZA). They differ only slightly in the solubility factor for carbon dioxide (alphaCO2, mmol/l x mmHg) and in the apparent pK(pK'), but more significantly in the plasma bicarbonate conc…
Identifying physical activity type in manual wheelchair users with spinal cord injury by means of accelerometers
2015
Objectives: The main objective of this study was to develop and test classification algorithms based on machine learning using accelerometers to identify the activity type performed by manual wheelchair users with spinal cord injury (SCI). Setting: The study was conducted in the Physical Therapy department and the Physical Education and Sports department of the University of Valencia. Methods: A total of 20 volunteers were asked to perform 10 physical activities, lying down, body transfers, moving items, mopping, working on a computer, watching TV, arm-ergometer exercises, passive propulsion, slow propulsion and fast propulsion, while fitted with four accelerometers placed on both wrists, c…
Imaging of Ventriculoperitoneal Shunt Complications: Comparison of Whole Body Low-Dose Computed Tomography and Radiographic Shunt Series.
2016
OBJECTIVE To determine diagnostic value and radiation exposure of low-dose computed tomography (LD-CT) compared to radiographic shunt series (SS) for the detection of ventriculoperitoneal (VP) shunt complications. METHODS Fourteen VP shunts were implanted in 7 swine cadavers. Mechanical complications were induced in 50% of VP shunts. Low-dose CT (80 kVp, 10 mAs, Pitch = 1.5) and SS were acquired. Dose area product (DAP) and effective doses for SS and LD-CT were collected. Scoring of diagnostic confidence and blinded readings of SS and CT data were performed. RESULTS The sensitivity of LD-CT was high (0.97; 95% confidence interval, 0.91-1.00) with excellent interobserver agreement (κ = 0.88)…
Button batteries and typical swallowed foreign bodies can be differentiated in high-resolution X-Rays.
2021
Abstract Background Button battery ingestions have emerged as an increasing medical issue in recent years, especially for children. The frequent use of these energy sources in small appliances and toys is responsible for their ubiquitous occurrence in households. In addition to other possible foreign bodies, button batteries are particularly dangerous as they can cause severe complications in the aerodigestive tract. Objective The study aimed for a detailed analysis of specific radiographic identifiers of button batteries and similarly configured potential esophageal foreign bodies in high-resolution X-ray scans. Methods A selection of potentially hazardous button batteries - in cases of in…