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Second Measurement (second + measurement)
Selected AbstractsGene expression measurements in the context of epidemiological studiesALLERGY, Issue 12 2008C. Bieli Background:, Gene expression measurements became an attractive tool to assess biological responses in epidemiological studies. However, collection of blood samples poses various technical problems. We used gene expression data from two epidemiological studies to evaluate differences between sampling methods, comparability of two methods for measuring RNA levels and stability of RNA samples over time. Methods:, For the PARSIFAL study, PBLC of 1155 children were collected using EDTA tubes in two countries. In the PASTURE study, tubes containing RNA-stabilizing solutions (PAXgene® Blood RNA Tubes; PreAnalytiX) were used to collect cord blood leucocytes of 982 children in five countries. Real-time PCR (conventional single tube assay and high-throughput low density arrays) was used to quantify expression of various innate immunity genes. In 77 PARSIFAL samples, gene expression was measured repeatedly during prolonged storage. Results:, In PARSIFAL (EDTA tubes) the median RNA yield after extraction significantly differed between the two centres (70 and 34 ng/,l). Collecting blood into an RNA-stabilizing solution markedly reduced differences in RNA yield in PASTURE (range of medians 91,107 ng/,l). The agreement [Spearman rank correlation (r)] between repeated measurements of gene expression decreased with increasing storage time [e.g., for CD14: r (first/second measurement) = 0.35; r (first/third measurement) = 0.03]. RNA levels measured with either the conventional method or low-density arrays were comparable (r > 0.9). Conclusion:, Collecting blood samples into tubes containing an RNA-stabilizing solution increases RNA yield and reduces its variability. Long-term storage of samples may lead to RNA degradation, requiring special attention in longitudinal studies. [source] Long-Term Variability of Markers of Bone Turnover in Postmenopausal Women and Implications for Their Clinical Use: The OFELY Study,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2003Patrick Garnero Abstract Bone marker variability has raised concern for its use in individual patients. Serum osteocalcin (formation) and CTX (resorption) were measured every year for 4 years in 268 postmenopausal women. Seventy percent to 80% of women classified as having high bone turnover at baseline were similarly classified by the same methods 4 years later. Introduction: High bone marker levels are a risk factor for osteoporosis in postmenopausal women, but variability of measurements has raised doubts about their clinical use in an individual patient. Methods: We studied 268 untreated postmenopausal women (50,81 years of age) belonging to a population-based prospective cohort. We collected fasting morning blood samples every year for 4 years to measure serum intact osteocalcin (OC) and serum C-terminal cross-linked telopeptide of type I collagen (CTX) as bone formation and resorption markers, respectively. Results: Serum OC and CTX remained stable during follow-up (+1.2%/year, p = 0.003 and ,0.13%/year, p = 0.70 for OC and S-CTX, respectively). At baseline, women were classified as having low (tertile 1), intermediate (tertile 2), or high (tertile 3) bone turnover. Agreement of classification between baseline and 4-year measurements was moderate (, [95% CI]: 0.51 [0.43,0.59] and 0.52 [0.44,0.60] for OC and S-CTX, respectively). Less than 10% of women in tertile 1 or 3 of either marker at baseline were found in the opposite tertile 4 years later. When the two markers were combined, only 2% of women at high turnover at baseline,defined as OC and/or S-CTX in tertile 3,were classified at low turnover 4 years later. Among women classified at high bone turnover at baseline (tertile 3), 70,80 % were also found at high turnover 4 years later. Among women in tertile 2, only 51% and 43% for OC and CTX, respectively, remained in the same tertile at the second measurement. Conclusions: Serum levels of bone formation and resorption markers are stable over 4 years in postmenopausal women, on average. The majority of women classified as having high bone turnover were similarly classified by the same methods 4 years later. However, 20,30 % of these women at risk for fracture would be incorrectly classified, suggesting that further investigation would be required to reduce the number of patients who would be treated unnecessarily if the decision was made on bone marker measurement. For women with intermediate levels, classification may be improved by a second measurement or by combining two markers. [source] Thermovoltaic properties of hornet silkMICROSCOPY RESEARCH AND TECHNIQUE, Issue 11 2006S. Volynchik Abstract In silk from the larval silk caps of the Oriental hornet Vespa orientalis (Hymenoptera, Vespinae), temperature-dependent changes in the electric voltage have been recorded, with rise in the voltage occurring mainly upon rise in the temperature between 10,36°C. The peak voltage was measured between 32,38°C and attained 240,360 mV, but with further increase in temperature, the voltage decreased, dropping to 0 mV at about 45,50°C. Upon second measurement (of same silk specimen), the voltage peak usually occurred later (by 8,9°C) and at higher temperature than in the first measurement. Continuous measurements during warming up to 30°C followed by cooling down to 15°C yielded an hysteresis between the warming "line" and the cooling "line", the former often straight and the latter usually curved. Maintaining the silk specimen at a fixed temperature for a prolonged period (hours) initially causes the voltage to rise, then remain steady, and finally drop. Boiling the silk caps in tap water for 7,10 min exerts some changes in the silk properties, mainly a decrease in voltage level. The general behavior of the silk suggests that it is a polymer endowed with the qualities of an organic semiconductor. The various properties of the larval silk are discussed in great detail. Microsc. Res. Tech., 2006. © 2006 Wiley-Liss, Inc. [source] Reliability of the Color Analog Scale: Repeatability of Scores in Traumatic and Nontraumatic InjuriesACADEMIC EMERGENCY MEDICINE, Issue 5 2009Blake Bulloch MD Abstract Objectives:, The objective was to assess in a pediatric emergency department (ED) the reliability of the color analog scale (CAS) for acute pain assessment, overall and between traumatic and nontraumatic pain etiology. Methods:, This was a prospective study of children aged 5 to 16 years in the ED of a children's hospital who had a complaint of pain. The CAS was administered to the patient at admission and at 30 minutes. To evaluate repeatability, a second measurement was obtained 1 minute following each assessment. This assumed there would be no substantial change in pain intensity within 1 minute. The authors used the intraclass correlation coefficient (ICC) to evaluate the repeatability of 1-minute interval measurements. Results:, A total of 170 patients were enrolled. The origin of pain was traumatic in 81 cases (48%). Regardless of pain etiology, the CAS scores were highly repeatable (r = 0.97, 95% confidence interval [CI] = 0.95 to 0.98). Conclusions:, The color analog scale is both a valid and a reliable self-reporting tool in the assessment of acute pain in children. [source] Isoresistive dynamometer measurement of trunk muscle velocity at different angular phases of flexion and extensionCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2001J. Surakka Isoresistive trunk muscle dynamometer is a potentially useful piece of equipment in evaluation of trunk muscle velocity, but to date, studies analysing the possibilities and limitations of such measurements are scarce. The aim of this study was to analyse the trunk muscle velocity in repetitive flexion and extension movements at three different angular phases, using an isoresistive trunk muscle dynamometer, and to assess the reliability of the measurements. The study population consisted of 120 healthy, sedentary men and women who volunteered for the study. The measurements were carried out before and after a 22-week training intervention programme. The results show that the peak velocities of the phases between 15 and 35° in flexion and 20,0° in extension (i.e. the second phases) correlated highly (r=0·99 in flexion and in extension) with the peak velocity of the whole movement ranging from ,5 to 55° in flexion and 40 to ,20° in extension. Correlations were high, both before and after the intervention. The LISREL model analysis showed high reliability of measurement for the second angular phases (in flexion and extension). According to the model, the correlation between the first and second measurement (with a 22-week training intervention in between) was 0·78 in flexion and 0·81 in extension. In conclusion, the angular phases from 15 to 35° in flexion and from 20 to 0° in extension represent the peak velocity of the whole movement. Negative residual correlations between the first and last angular phases in the LISREL model reflect the way of performing the movement: the faster the start the slower the end, and vice versa. [source] | ||||||||||