Useful Aid (useful + aid)

Distribution by Scientific Domains

Selected Abstracts

Placental thickness in the first half of pregnancy

Theera Tongsong MD
Abstract Purpose This study was conducted to establish normal values of placental thickness during the first half of pregnancy. Methods Normal pregnant women with singleton pregnancies between 8 and 20 weeks of gestation were recruited into the study. All the newborns were normal at birth. Placental thickness was measured perpendicularly through the thickest part of the placenta on transabdominal scans. The placental thickness data were analyzed for mean, standard deviation, 95% confidence interval, and 2.5th, 5th, 50th, 95th, and 97.5th percentile for each week of gestational age. The best-fit mathematical model was derived by regression analysis. Results The total number of measurements was 333 and the number of measurements for each week of gestational age ranged from 9 to 37. Regression analysis yielded the following linear equation of the relationship: placental thickness (in mm) = gestational age (in weeks) × 1.4,5.6 (r = 0.82). Conclusion We have established a nomogram for placental thickness. This resource may be a useful aid in the early detection of placental abnormalities, such as hydropic placenta secondary to hemoglobin Bart's disease. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:231,234, 2004; Published online in Wiley InterScience ( DOI: 10.1002/jcu.20023 [source]

Measurement of Fractional Flow Reserve to Assess Moderately Severe Coronary Lesions: Correlation with Dobutamine Stress Echocardiography

Background: New techniques to evaluate coronary artery disease, such as calculation of myocardial fractional flow reserve (FFR) with a guidewire and pressure transducer, provide a functional assessment of coronary lesions. The present study was designed to determine the correlation between FFR and dobutamine stress echocardiography in patients with moderately severe coronary stenosis in order to judge the usefulness of FFR for commonly encountered clinical problems. Methods and Results: We studied 21 patients with 23 moderately severe coronary artery stenoses on angiography. The FFR was calculated and dobutamine stress echocardiography was performed to detect ischemia. Of the 16 stenoses with a negative FFR (, 0.75), dobutamine echocardiography also was negative. In the seven stenoses with a positive FFR (< 0.75), dobutamine echocardiography was positive in three. The efficacy of FFR in detecting ischemia that was confirmed with stress echocardiography was sensitivity 100%, specificity 80%, positive and negative predictive value 42.8%, and 100%. respectively, with a global predictive value 82.6%. A moderate degree of correlation was found between the two diagnostic tests (kappa [k] = 0.51). Conclusions: FFR correlates moderately well with dobutamine stress echocardiography in the assessment of moderately severe lesions in patients for whom coronary arteriography is usually indicated. However, its high negative predictive value makes FFR a useful aid in reaching clinical decisions promptly in the hemodynamics laboratory. [source]

External anal sphincter responses after S3 spinal root surface electrical stimulation

Giuseppe Pelliccioni
Abstract Aims The aim of this study is to present the normative data of direct and reflex motor anal sphincter responses, simultaneously evoked by S3 surface electrical stimulation. By this method, it is possible to test the functional integrity of the nervous pathways activated during sacral neuromodulation (SNM). Methods Twenty healthy subjects were studied. Motor-evoked potentials (MEPs) were recorded by concentric needle electrode from external anal sphincter (EAS). Electrical stimulation was applied by means of a bipolar surface electrode over the S3 right or left sacral foramina. Results Direct (R1) and reflex responses (R2 and R3) were found at latencies of 6.98, 25.12, and 50.31 msec, respectively. The two first responses were recorded in all the cases; the last response is steadily recorded in 17 out of 20 subjects. Conclusions Our data can serve as reference values for future study in patients with pelvic floor dysfunction. EAS responses following S3 percutaneous electrical stimulation can represent a useful aid in the selection of candidates to SNM. Neurourol. Urodynam. 25:788,791, 2006. © 2006 Wiley-Liss, Inc. [source]

Fragmentation pathways of some benzothiophene radical cations formed by atmospheric pressure chemical ionisation

Lisandra Cubero Herrera
Polycyclic aromatic sulfur-containing compounds (PASHs) are commonly found in fossil fuels and are of considerable importance in environmental studies. This work presents detailed studies on the fragmentation patterns of radical cations formed from four representative PASHs, benzo[b]thiophene, dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene, using tandem atmospheric pressure chemical ionization mass spectrometry (APCI-MS/MS). Understanding these fragmentation patterns can be a useful aid in the analysis of PASHs employing APCI or electron ionization (EI-MS/MS), either alone or in conjunction with liquid or gas chromatography. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Modelling Students at Risk

Diane M. Dancer
Using a sample of several hundred students we model progression in a first-year econometrics course. Our primary interest is in determining the usefulness of these models in the identification of ,students at risk'. This interest highlights the need to distinguish between students who drop the course and those who complete but who ultimately fail. Such models allow identification and quantification of the factors that are most important in determining student progression and thus make them a potentially useful aid in educational decision making. Our main findings are that Tertiary Entrance Rank (TER), mathematical aptitude, being female and attendance in tutorials are all good predictors of success but amongst these factors only attendance is significant in discriminating between students who fail and those who discontinue. Also, there are differences across degree programs and, in particular, students in Combined Law are very likely to pass but, if they are at risk, they are much more likely to discontinue than to fail. [source]