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Paired Data (paired + data)
Selected AbstractsColor M-Mode Flow Propagation Velocity: Is It Really Preload Independent?ECHOCARDIOGRAPHY, Issue 8 2005Shih-Kai Lin M.D. Objective: This study investigates the change in flow propagation velocity (FPV) in uremic patients who undergo regular hemodialysis (H/D). Materials and Methods: We studied 93 uremic patients (44 men and 49 women; 59 ± 14-years-old) receiving regular hemodialysis. Patients were separated by baseline left ventricular ejection fraction (LVEF): 71 patients with LVEF > 50% (group 1), 13 patients with LVEF 35,50% (group 2), 7 patients with LVEF < 35% (group 3). All patients were in sinus rhythm before H/D. They received complete transthoracic echocardiographic examinations. Flow propagation velocity was measured by color M-mode echocardiography in apical four chambers view. All these parameters were obtained before and after H/D. Paired data were compared. According to different H/D amounts, we viewed the FPV response after H/D in variant baseline LVEF groups. Result: The baseline FPV became lower in patients with low LVEF. After H/D, obvious decrement of FPV occurred in group 1, but there were no obvious changes in groups 2 and 3. In fact, a slight increment of FPV was found in group 3. In patients with baseline LVEF > 50%, FPV after H/D was almost always lower, regardless of H/D amount. But there was different response in patients with baseline LVEF < 50%. Conclusion: Flow propagation velocity is preload independent in patients with LVEF < 50%, but it is preload-dependent in patients with LVEF > 50%. [source] Waist circumference in relation to body perception reported by Finnish adolescent girls and their mothersACTA PAEDIATRICA, Issue 3 2009JS Van Vliet Abstract Aim: To study how waist circumference (WC) relates to body perception in adolescent girls and to maternal perception of the girl's body size. Methods: Three hundred and four girls, 11,18 years, were measured for height, weight and WC. 294 girls provided self-report data on weight, height and body image before anthropometric measurements. Paired data from 237 girls and mothers on perception of the girls' body size were collected. Results: In girls, self-reported weight indicated awareness of actual body size. The girls' body perception showed an overestimation of body size relative to international reference values for body mass index (BMI) (p < 0.05), but not for WC. Girls' body perception exceeded that of their mothers (p < 0.05). Maternal perception agreed better than the girls' perception with international reference values for BMI (p < 0.05). No significant difference between mothers and girls were found concerning agreement of body perception with international reference values for WC. Conclusion: WC rather than BMI agrees with perception of body size, possibly due to its relation to abdominal fat at different ages. For effective prevention and treatment programmes for weight-related health problems among adolescent girls, we recommend measuring WC to diminish the discrepancy between measured and perceived body size. [source] Cervical cytology reading times: A comparison between thinprep imager and conventional methodsDIAGNOSTIC CYTOPATHOLOGY, Issue 9 2007Elizabeth Davey MBBS Abstract We aimed to compare the times cytologists spend reviewing cervical cytology slides processed by the ThinPrep Imager® (TPI) with times they spend examining conventional cytology (CC) slides. We also aimed to examine the effect of cytologists' experience on reading times. Using a cross-sectional analytical design, we analyzed routine laboratory data, collected retrospectively over 7 months, for 41 cytologists, including paired data for 20 who read both TPI and CC slides. For the 20 cytologists who read both types of cytology, the mean reading rate was 13.3 slides per hour for TPI slides and 6.1 slides per hour for CC slides. The mean within-reader difference between TPI and CC rates was 7.2 slides per hour (P < 0.001). For CC reading, mean times did not differ between those who were additionally trained to read TPI slides and those who only read CC. Slower readers had greater increases in speed when using the TPI compared with CC reading than did faster readers (P < 0.001). More experienced cytologists tended to read CC slides more quickly than did those less experienced, but experience did not affect TPI reading times or within-reader differences in reading times between cytology types. The TPI significantly reduced reading times compared with CC. This reduction was greater amongst slower readers, and was unrelated to experience. Diagn. Cytopathol. 2007;35:550,554. © 2007 Wiley-Liss, Inc. [source] An Ovine Model of Chronic Heart Failure: Echocardiographic and Tissue Doppler Imaging CharacterizationJOURNAL OF CARDIAC SURGERY, Issue 1 2006M.Sc., Nicolas Borenstein D.V.M. In order to validate novel surgical or pharmacological treatments, reproducible animal models of left ventricular dysfunction are necessary. In the current study, we report our data and experience with a model of toxin-induced heart failure in the sheep. Methods: Sequential intracoronary injections of doxorubicin (0.75 mg/kg) were carried out every 2 weeks until standard echocardiographic and tissue Doppler imaging detection of myocardial systolic dysfunction. The animals were assessed 1 month later and harvested. Indices of cardiac function from baseline to last day of protocol were recorded and their differences were evaluated by a Wilcoxon rank test for paired data. Results: Ten sheep received 2.5 ± 0.7 intracoronary injections of a cumulative dose of 88.8 ± 25 mg/m2 doxorubicin. All available parameters demonstrated signs of severe cardiac dysfunction with statistical significance. All hearts demonstrated severe histological lesions, some of which were consistent with doxorubicin-induced toxicity. Conclusions: The present study shows that this ovine model is reproducible and stable. It can therefore be relevant to the study of chronic heart failure. It will be incorporated in our future studies concerning novel treatments (such as cell therapy) of nonischemic dilated cardiomyopathy. [source] Reduced oxidative stress in parallel to improved cardiac performance one year after selective removal of anti-beta 1-adrenoreceptor autoantibodies in patients with idiopathic dilated cardiomyopathy: data of a preliminary study,JOURNAL OF CLINICAL APHERESIS, Issue 3 2005Ingolf Schimke Abstract Patients with idiopathic dilated cardiomyopathy (IDC) were treated with selective immunoadsorption to remove anti-beta 1-adrenoreceptor autoantibodies (anti-beta1A-AB). After one year, the effect on cardiac performance and oxidative stress was tested. Extracorporeal immunoadsorption of the whole IgG class in IDC patients for the removal of anti-beta1A-AB reduced oxidative stress in parallel to an improvement of cardiac performance. However, the non-specificity of IgG adsorption means that these beneficial effects cannot be attributed exclusively to anti-beta1A-AB removal. In an open clinical pilot study enrolling 8 patients with IDC prior to and one year after selective immunoadsorption of anti-beta1A-AB, plasma markers for oxidative stress,thiobarbituric acid-reactive substances (TBARS), lipid peroxides (LPO) and anti-oxidized low-density lipoprotein autoantibodies (anti-oxLDL-AB),were measured in parallel to evaluation of the left ventricular function using conventional echocardiography and wall motion analysis by tissue Doppler imaging. After one year, TBARS (Wilcoxon test with bootstrapping simulation for paired data: 95% confidence interval of the P value 0.020 to 0.029) and anti-oxLDL-AB (P = 0.025 to 0.035) were decreased in parallel to an improvement of the peak systolic wall motion velocity (P = 0.006 to 0.01) and left ventricular ejection fraction (P = 0.002 to 0.02). For changes over the study period, a direct correlation with borderline significance (P = 0.076) was calculated for TBARS to the left ventricular diameter in the diastole. One year after selective immunoadsorption for anti-beta1A-AB removal, patients with ICD show a reduction in oxidative stress and a parallel improvement in cardiac performance. J. Clin. Apheresis © 2005 Wiley-Liss, Inc. [source] Evaluation of a Novel Real-Time Continuous Glucose-Monitoring System for Use in CatsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010S. Moretti Background: The Guardian REAL-Time is a continuous glucose-monitoring system (CGMS) recently developed to provide instantaneous interstitial glucose concentrations; the system does not require a monitor being fixed to the animal. Hypothesis: The CGMS provides accurate and reproducible real-time readings of glucose concentration in cats. Animals: Thirty-two diabetic cats, 2 cats with suspected insulinoma, and 5 healthy cats. Methods: Prospective, observational study. CGMS accuracy was compared with a reference glucose meter at normal, high, and low blood glucose concentrations using error grid analysis. Reading variability of 2 simultaneously used CGMS was determined in diabetic cats by calculating correlation and percentage of concordance of paired data at different glycemic ranges. The time interval between increasing glycemia and a rise in interstitial fluid glucose measured by the CGMS was assessed in healthy cats receiving glucose IV; the time point of maximal increase in interstitial glucose concentrations was calculated. Results: The CGMS was 100, 96.1, and 91.0% accurate at normal, high, and low blood glucose concentrations. Measurements deviated from reference by ,12.7 ± 70.5 mg/dL at normal, ,12.1 ± 141.5 mg/dL at high, and ,1.9 ± 40.9 mg/dL at low glucose concentrations. Overall, paired CGMS readings correlated significantly (r= 0.95, P < .0001) and concordance was 95.7%. The median delay after IV administration of glucose to an increase in interstitial glucose was 11.4 minutes (range: 8.8,19.7 minutes). Conclusions and Clinical Importance: Although some readings substantially deviated from reference values, the CGMS yields reproducible results, is clinically accurate in cats with hyperglycemia and euglycemia, and is slightly less accurate if blood glucose concentrations are low. Rapidly increasing interstitial glucose after a glycemic rise suggests that the CGMS is suitable for real-time measurement under clinical conditions. [source] The Wilcoxon Signed Rank Test for Paired Comparisons of Clustered DataBIOMETRICS, Issue 1 2006Bernard Rosner Summary The Wilcoxon signed rank test is a frequently used nonparametric test for paired data (e.g., consisting of pre- and posttreatment measurements) based on independent units of analysis. This test cannot be used for paired comparisons arising from clustered data (e.g., if paired comparisons are available for each of two eyes of an individual). To incorporate clustering, a generalization of the randomization test formulation for the signed rank test is proposed, where the unit of randomization is at the cluster level (e.g., person), while the individual paired units of analysis are at the subunit within cluster level (e.g., eye within person). An adjusted variance estimate of the signed rank test statistic is then derived, which can be used for either balanced (same number of subunits per cluster) or unbalanced (different number of subunits per cluster) data, with an exchangeable correlation structure, with or without tied values. The resulting test statistic is shown to be asymptotically normal as the number of clusters becomes large, if the cluster size is bounded. Simulation studies are performed based on simulating correlated ranked data from a signed log-normal distribution. These studies indicate appropriate type I error for data sets with ,20 clusters and a superior power profile compared with either the ordinary signed rank test based on the average cluster difference score or the multivariate signed rank test of Puri and Sen (1971, Nonparametric Methods in Multivariate Analysis, New York: John Wiley). Finally, the methods are illustrated with two data sets, (i) an ophthalmologic data set involving a comparison of electroretinogram (ERG) data in retinitis pigmentosa (RP) patients before and after undergoing an experimental surgical procedure, and (ii) a nutritional data set based on a randomized prospective study of nutritional supplements in RP patients where vitamin E intake outside of study capsules is compared before and after randomization to monitor compliance with nutritional protocols. [source] Nucleolar size in choroidal and ciliary body melanomas and corresponding hepatic metastasesACTA OPHTHALMOLOGICA, Issue 4 2010Rana'a T. Al-Jamal Abstract. Purpose:, This study aimed to investigate the relationship between hepatic metastasis and the mean diameter of the 10 largest nucleoli (MLN) in uveal melanoma. Methods:, A cross-sectional histopathological analysis of 37 metastases (13 surgical or needle biopsies, 24 autopsies) and corresponding primary choroidal and ciliary body melanomas was conducted, using statistical tests appropriate for paired data. The largest nucleoli were measured from digital photographs of silver-stained sections along a 5-mm-wide linear field. Confounders considered were presence of epithelioid cells and microvascular density (MVD), counted as the number of discrete elements labelled by monoclonal antibody QBEND/10 to the CD34 epitope. Results:, Hepatic metastases had more frequent epithelioid cells (p = 0.0047) and a higher MVD (median difference, 7.5 counts/0.313 mm2 more; p = 0.044) than their corresponding primary tumours. Hepatic metastases, especially in autopsy specimens rather than surgical biopsies, tended to have a smaller MLN (median 3.6 ,m) than the corresponding primary tumour (median difference, 0.55 ,m; p = 0.066). The MLN in hepatic metastases was not associated with presence of epithelioid cells and MVD. Overall survival after diagnosis of metastasis was comparable whether hepatic metastases had a large or small MLN (p = 0.95), whereas a high MVD tended to be associated with shorter survival (p = 0.096) among the 13 patients with known survival. Conclusions:, The results suggest that MLN is not a useful marker for assessing prognosis after diagnosis of hepatic metastasis from uveal melanoma. [source] Photodynamic therapy for chronic central serous chorioretinopathyACTA OPHTHALMOLOGICA, Issue 3 2010José M. Ruiz-Moreno Abstract. Purpose:, This study aimed to evaluate the efficacy of photodynamic therapy (PDT) in treating chronic central serous chorioretinopathy (CSC). Methods:, We describe a non-randomized, multicentre, interventional case series. A total of 82 eyes of 72 patients with chronic CSC were treated by conventional PDT. LogMAR best corrected visual acuity (BCVA) (ETDRS charts) and central foveal thickness (CFT) measured by optical coherence tomography before and after PDT, number of PDT treatments and complications were used as outcome indicators. Results:, Mean follow-up was 12 ± 10 months and mean age was 46 ± 10 years. Mean logMAR BCVA changed from 0.53 (standard deviation [SD] 0.43) before PDT to 0.38 (SD 0.41) at 3 months and 0.48 (SD 0.50) at 6 months (p < 0.0001 and p = 0.007, respectively, Student's t- test for paired data). Mean BCVA at the end of follow-up was 0.37 (SD 0.45; p < 0.0001 from baseline). Macular detachment was resolved and subretinal fluid (SRF) disappeared in all cases. Central foveal thickness decreased from 325 ,m (SD 95), to 229 ,m (SD 70) at 1 month after PDT, 206 ,m (SD 68) at 3 months, and 202 ,m (SD 76) at 6 months (all p < 0.0001, Student's t- test for paired data). No cases developed severe visual loss or complications derived from PDT. Reactive retinal pigment epithelium hypertrophy appeared in nine cases after PDT. Conclusions:, Photodynamic therapy with verteporfin may be useful in chronic CSC for improving BCVA and reducing SRF and CFT. Randomized studies with longer follow-up are needed to assess the real role of this treatment in chronic CSC. [source] | ||||||||||