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Mean SD (mean + sd)
Selected AbstractsCircadian Profile of Cardiac Autonomic Nervous Modulation in Healthy Subjects:JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2003Differing Effects of Aging, Gender on Heart Rate Variability Introduction: Although heart rate variability (HRV) has been established as a tool to study cardiac autonomic activity, almost no data are available on the circadian patterns of HRV in healthy subjects aged 20 to 70 years. Methods and Results: We investigated 166 healthy volunteers (81 women and 85 men; age 42 ± 15 years, range 20,70) without evidence of cardiac disease. Time-domain HRV parameters were determined from 24-hour Holter monitoring and calculated as hourly mean values and mean 24-hour values. All volunteers were fully mobile, awoke around 7 A.M., and had 6 to 8 hours of sleep. Circadian profiles of vagus-associated HRV parameters revealed a marked day-night pattern, with a peak at nighttime and a plateau at daytime. The characteristic nocturnal peak and the day-night amplitude diminished with aging by decade. Estimates of overall HRV (geometric triangular index [TI], SD of NN intervals [SDNN]) and long-term components of HRV (SD of the averages of NN intervals for all 5-min segments [SDANN]) were low at nighttime and increased in the morning hours. There was a significant decline of 24-hour values of all HRV parameters (P < 0.001) and a strong negative correlation (P < 0.001) with increasing age. Mean 24-hour RR interval (P < 0.001), SDNN, mean SD of NN intervals for all 5-minute intervals (SDNNi), and SDANN (all P < 0.01) were significantly higher in men. Younger men also exhibited significantly higher values for vagus-associated parameters (root mean square successive difference [rMSSD], P < 0.05; SDNNi, P < 0.01); however, gender differences diminished with increasing age. Conclusion: Normal aging is associated with a constant decline of cardiac vagal modulation due to a significant decrease of nocturnal parasympathetic activity. The significant gender-related difference of HRV decreases with aging. These findings emphasize the need to determine age-, gender-, and nycthemeral-dependent normal ranges for HRV assessment. (J Cardiovasc Electrophysiol, Vol. 14, pp. 791-799, August 2003) [source] Cross-linked N-telopeptide of type I collagen (NTx) in urine as a predictor of periprosthetic osteolysisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 7 2006Thord von Schewelov Abstract Periprosthetic osteolysis is often nonsymptomatic and hard to visualize by conventional radiography. Cross-linked N-telopeptide of type I collagen (NTx), a marker of osteoclast mediated bone resorption, has been suggested to evaluate local particulate-induced osteolysis in patients operated on with a total hip prosthesis. Urine specimens were sampled after hip joint replacement in 160 patients. NTx was analyzed by a commercially available ELISA kit. Osteolysis was identified in the acetabulum and confirmed at operation. Using analysis of covariance to correct for differences in age, gender, and time after operation, NTx (mean SD) was 36,±,12 BCE/nM creatinine in patients with osteolysis (n,=,33) and 27,±,13 BCE/nM creatinine in patients without osteolysis (n,=,127) (p,=,0.003). Eighteen hips of 38 (47%), demonstrating an annual wear of more than 0.2 mm and an NTx value above 29 BCE/nM creatinine, had been revised due to osteolysis. The osteolysis prevalence in this group was increased 10 times (CI 4-23, p,<,0.05). Indeed, NTx release and annual wear were both associated with increased prevalence of osteolysis, however, independently of each other. NTx seems a feasible marker of periprosthetic osteolysis. A preoperative baseline NTx level is likely needed for its use as a predictor of periprosthetic osteolysis in individual cases. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1342,1348, 2006 [source] Stimulus size and the variability of the threshold response in the central and peripheral visual fieldOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2002L. S. Kim Purpose:, The investigation of the peripheral visual field has shown considerable interest for the investigation of field loss attributed to anticonvulsant therapy. The purpose was to determine the within-visit between-subject, the between-visit between-subject, and the between-location variability of the threshold response in the normal eye with increase in stimulus eccentricity out to 60° as a function of stimulus size. Methods:, Forty-eight normal subjects attended for a total of three visits (mean age = 49.5 years, SD = 18.9, range 22,84 years). At the first visit, one randomly assigned eye of each subject was examined with the Humphrey Field Analyzer 750 (Carl Zeiss, Jena, Germany) and the Full Threshold algorithm using Programs 30,2 and 60,4 and stimulus sizes III and V. The combination of stimulus size and of program, and the order of the combination within- and between-sessions, were randomized for each subject. The results of the first visit were considered as a familiarization period and were discarded. The protocol at the second and third visits was identical to that at the first visit for each subject. Results:, The ratio of the SD of the group mean sensitivity was determined at each stimulus location for stimulus size III compared with stimulus size V for Programs 30,2 and 60,4 at visit 3. The SDs were greater than unity for Program 30,2 (p < 0.0001) and for Program 60,4 (p < 0.0001) indicating greater variability for the size III stimulus. The SDs were also greater than unity for the central inner zone (p < 0.0001), central outer zone (p < 0.0001) and peripheral inner zone (p < 0.0001). The ratios in the peripheral outer zone were not quite greater than unity (p = 0.054). The ratios increased with increase in eccentricity by up to 2.7 times between 15° and 30° eccentricity and by up to 2.7 times between 30° and 60° eccentricity. The group mean ratio did not vary significantly between the two visits for Program 30,2 stimulus size III (p = 0.563), Program 60,4 stimulus size III (p = 0.935) and for Program 60,4 stimulus size V (p = 0.005). However, the group mean SD was lower at visit 3 compared with visit 2 for Program 30,2 stimulus size V (p = 0.0004). The SDs associated with the extreme peripheral locations in the superior and nasal fields were smaller for stimulus size III because the threshold was frequently attenuated by lid and facial contour. Conclusions:, Considerably narrower confidence limits for normality for the peripheral regions of Program 30,2 and for 60,4 are demonstrated with the use of Goldmann size V. [source] Reliability results of straylight measurements using the C-QuantACTA OPHTHALMOLOGICA, Issue 2008A CERVINO Purpose Assessment of repeatability and reproducibility of straylight measures with the C-Quant straylightmeter (Oculus AG, Germany), effect of age on reliability measures and correlation of measures determined with new methods of scatter determination. Methods Results from different studies will be presented. For repeatability assessment, 20 eyes (age 26.9±2.7 years) were examined with the C-Quant, taking 10 consecutive readings. 5 subjects were also examined on 5 consecutive days to assess reproducibility. Repeated measures from 84 subjects, age range 19-86 years, were analysed to assess the effect of patient's age. Software was developed to quantify scatter from centroid patterns obtained using a clinical aberrometer(WASCA, Zeiss) based on previous work by Donnelly & Applegate, and 3 values were obtained on 10 eyes. 3 measures were also made with the C-Quant. Preliminary results comparing the C-Quant and the StarLight hallometer will also be presented. Results Results failed to show differences between readings taken within the same session (mean SD 0.07, p>0.05) or between sessions (mean SD 0.05, p>0.05). Variability of intrasession measurements was not significant for subjects of different age (p=0.094). After removal of incomplete patterns, good correlation was achieved between psychometric and objective measures despite small sample size (n=6; r= -0.831, p=0.040). Conclusion The C-Quant straylightmeter is repeatable and reliable for retinal straylight assessment on human eyes. Age does not decrease repeatability eventhough they feel more insecure about their ability to perform the test. Psychometrical determination of straylight showed remarkably high correlation with objective measures of scatter on young healthy subjects. [source] | ||||||||||