Search results for "percentile"
showing 10 items of 103 documents
Diffusion-weighted MRI of the lung with hyperpolarized helium-3: A study of reproducibility
2005
Purpose To determine the reproducibility of several parameters of the ADC measurement by calculating the scan-to-scan intrasubject variability. Materials and Methods Measurements were performed using a gradient-echo sequence with a bipolar gradient for diffusion weighting (b = 3.89 sec/cm2). Five patients with pulmonary emphysema, and six healthy-lung volunteers were included in the study. Images were acquired after inspiration of 3He during a single inspiratory breath-hold. To assess the reproducibility, the measurement was performed twice (time between measurements = 20 minutes) without repositioning the subjects. Analysis was performed on the basis of region-of-interest (ROI) analysis an…
Immunonephelometric determination of the C4b-binding protein.
1993
A fully mechanised immunonephelometric method for the rapid and specific determination of C4b-binding protein (C4b-BP) in citrated plasma is described. The method utilizes commercially available rabbit antiserum against human C4b-BP and a nephelometer analyser. A single determination can be performed within 6 min, requiring 80 microliters sample volume. The measuring range is about 10 to 200% of normal C4b-BP. Precision is characterized by intraassay coefficients of variation between 1.5% and 2.8%, and interassay coefficients of variation between 4.0% and 4.6% for the same C4b-BP concentrations. The nephelometry of C4b-BP was correlated with electroimmunodiffusion (Laurell technique; r = 0.…
Agreement in Asthmatics' Perception of Dyspnea During Acute and Chronic Obstruction
2005
Objective Three types of asthmatic patients can be identified during periods of clinical stability: “poor perceivers,” “normal perceivers,” and “over perceivers.” When asthmatics undergo bronchial challenge in the laboratory, the same distinctions in type of perception can be observed. The aim of the present study was to determine the level of agreement between the 2 situations. Patients and methods A total of 93 patients with persistent moderate asthma (36 men and 57 women; mean age 40 years) were studied. We asked them to assess their dyspnea on a modified Borg scale when stable and after each histamine dose in a bronchial provocation test. When a patient's Borg scale assessment in stable…
[Saccharin test for the study of mucociliary clearance: reference values for a Spanish population].
2008
Objective Mucociliary transport is an important defense mechanism for the airways. The aim of this study was to establish reference values for nasal mucociliary clearance time (MCT) by means of the saccharin test. Subjects and Methods A cross-sectional, descriptive, observational study was performed. The variables studied were nasal MCT, age, and sex. We included 249 healthy nonsmokers (134 male and 115 female subjects) aged over 10 years and stratified the sample by age. To establish reference values, percentiles were calculated and lower and upper limits of normal were established at the 2.5 and 97.5 percentiles, respectively. The association between nasal MCT and the main study variables…
Establishing the upper reference limit of Galectin-3 in healthy blood donors
2017
Introduction Galectin-3 (Gal-3) is an independent predictor of poor outcomes and mortality in patients with heart failure (HF). Thus, it has been proposed as a reliable prognostic biomarker for HF. The definition of reference intervals is mandatory for interpreting the findings of experimental studies and encouraging the routine use of biomarkers in clinical practice. To date, no study assessed the reference intervals of Gal-3 and identified the biological variables that affect its concentration in a well-defined healthy population. The aim of this study was to determine the upper reference limit (URL) of Gal-3 in a highly reliable population of healthy subjects. Materials and methods We re…
The value of the short-term fetal heart rate variation for timing the delivery of growth-retarded fetuses.
2008
OBJECTIVE: To assess the clinical value of the short-term fetal heart rate variation (STV) for timing the delivery of severely growth-retarded fetuses, many associated with pre-eclampsia. DESIGN: Retrospective cohort study. SETTING: John Radcliffe Maternity Hospital, Oxford, UK. POPULATION: Two hundred and fifty-seven fetuses with a birthweight less than third percentile and a last computerised cardiotocography performed within 24 h of delivery. METHODS: Analysis of the relationship between antepartum STV and the perinatal outcome. MAIN OUTCOME MEASURES: Stillbirth rate and the acid-base status at birth. RESULTS: There were no stillbirths or neonatal deaths (NNDs) within 24 h in the study p…
Motion analysis in the field of dentistry: a kinematic comparison of dentists and orthodontists
2016
Objectives: To conduct a kinematic comparison of occupational posture in orthodontists and dentists in their workplace. Design: Observational study. Setting: Dentist surgeries and departments of orthodontics at university medical centres in Germany. Participants: A representative sample of 21 (10 female, 11 male) dentists (group G1) and 21 (13 female, 8 male) orthodontists (G2) with one male dropout in G2. Outcome measures: The CUELA (computer-assisted acquisition and long-term analysis of musculoskeletal loads) system was used to analyse occupational posture. Parallel to the recording through the CUELA system, a software-supported analysis of the activities performed (I: treatment; II: off…
Effects of Particulate Matter on the Incidence of Respiratory Diseases in the Pisan Longitudinal Study
2020
The current study aimed at assessing the effects of exposure to Particulate Matter (PM) on the incidence of respiratory diseases in a sub-sample of participants in the longitudinal analytical epidemiological study in Pisa, Italy. Three hundred and five subjects living at the same address from 1991 to 2011 were included. Individual risk factors recorded during the 1991 survey were considered, and new cases of respiratory diseases were ascertained until 2011. Average PM10 and PM2.5 exposures (µ
Is ultraviolet exposure acquired at work the most important risk factor for cutaneous squamous cell carcinoma? Results of the population-based case-c…
2018
Background Squamous cell carcinoma (SCC) is among the most frequent types of cancer constituting a significant public health burden. Prevention strategies focus on limiting UV-exposure during leisure time. However, the relative impact of occupational and non-occupational UV-exposure for SCC occurrence is unclear. Objectives To investigate the association between occupational and non-occupational UV-exposure with SCC in a multicenter population-based case-control study hypothesizing that high occupational UV-exposure increases the risk for SCC. Methods Consecutive patients with incident SCC (n=632) were recruited from a German national dermatology network. Population-based controls (n=996) w…
Trace elements in scalp hair samples from patients with relapsing-remitting multiple sclerosis
2015
Background Epidemiological studies have suggested a possible role of trace elements (TE) in the etiology of several neurological diseases including Multiple Sclerosis (MS). Hair analysis provides an easy tool to quantify TE in human subjects, including patients with neurodegenerative diseases. Objective To compare TE levels in scalp hair from patients with MS and healthy controls from the same geographic area (Sicily). Methods ICP-MS was used to determine the concentrations of 21 elements (Ag, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn) in scalp hair of 48 patients with relapsing–remitting Multiple Sclerosis compared with 51 healthy controls. Results MS …