3 resultados para Non-parametric density estimator
Resumo:
Objective: To compare measurements of the upper arm cross-sectional areas (total arm area,arm muscle area, and arm fat area of healthy neonates) as calculated using anthropometry with the values obtained by ultrasonography. Materials and methods: This study was performed on 60 consecutively born healthy neonates: gestational age (mean6SD) 39.661.2 weeks, birth weight 3287.16307.7 g, 27 males (45%) and 33 females (55%). Mid-arm circumference and tricipital skinfold thickness measurements were taken on the left upper mid-arm according to the conventional anthropometric method to calculate total arm area, arm muscle area and arm fat area. The ultrasound evaluation was performed at the same arm location using a Toshiba sonolayer SSA-250AÒ, which allows the calculation of the total arm area, arm muscle area and arm fat area by the number of pixels enclosed in the plotted areas. Statistical analysis: whenever appropriate, parametric and non-parametric tests were used in order to compare measurements of paired samples and of groups of samples. Results: No significant differences between males and females were found in any evaluated measurements, estimated either by anthropometry or by ultrasound. Also the median of total arm area did not differ significantly with either method (P50.337). Although there is evidence of concordance of the total arm area measurements (r50.68, 95% CI: 0.55–0.77) the two methods of measurement differed for arm muscle area and arm fat area. The estimated median of measurements by ultrasound for arm muscle area were significantly lower than those estimated by the anthropometric method, which differed by as much as 111% (P,0.001). The estimated median ultrasound measurement of the arm fat was higher than the anthropometric arm fat area by as much as 31% (P,0.001). Conclusion: Compared with ultrasound measurements using skinfold measurements and mid-arm circumference without further correction may lead to overestimation of the cross-sectional area of muscle and underestimation of the cross-sectional fat area. The correlation between the two methods could be interpreted as an indication for further search of correction factors in the equations.
Resumo:
To assess the degree of discomfort caused by length measurement in neonates, performed with one or both lower limbs extended, on the first and second day after birth, with either one or both lower limbs extended. METHODS: Healthy full-term neonates were systematically sampled during the months of February and March 2004. Crown-heel length was measured, using a 1-mm precision neonatometer, at approximately 8 h and 32 h after birth, with one and both lower limbs extended. The Neonatal Facial Coding System was used to assess discomfort during measurements. Data were analysed by parametric and non-parametric tests as appropriate. RESULTS: Whatever the measurement technique, discomfort scores are significantly higher during the length measurement than at baseline. Whenever length measurements are performed, discomfort scores are significantly higher when extending both lower limbs rather than one lower limb (p < 0.006). The measured length is greater with one lower limb extended; however, the difference decreases over time, being 0.19 cm (95% CI 0.1-0.3; p < 0.001) at approximately 32 h of age. No significant differences in length were found between measurements at approximately 8 or 32 h, regardless of the technique used. The best correlation between length measurements with one or both lower limbs extended was observed at approximately 32 h after birth (r = 0.98). CONCLUSION: Measuring crown-heel length is a distressful procedure for the neonate. Measurements with one lower limb extended result in less discomfort than when both lower limbs are extended, without decreasing the accuracy.
Resumo:
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: * In previous work, we showed a long-term and concentration-dependent beneficial effect of the non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) on high-density lipoproteins (HDL) in human immunodeficiency virus (HIV)-infected patients. * Furthermore, it has been suggested that instead of the current practice of only measuring HDL-chelesterol values, the evaluation of HDL function, namely its antioxidant properties, might be an improved tool for identifying subjects at increased risk for cardiovascular events. * Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is responsible for HDL antioxidant function. WHAT THIS STUDY ADDS: * In the present work, we studied the effect of EFV on the activity of PON-1 and showed, for the first time, that EFV-based antiretroviral therapy is associated with a better antioxidant function, i.e. with a higher PON-1 activity. AIMS: A long-term and concentration-dependent beneficial effect of efavirenz (EFV) on cholesterol associated with high-density lipoprotein (HDL-c) in human immunodeficiency virus (HIV)-infected patients has been documented. Furthermore, it has been suggested that, instead of the current practice of only measuring HDL-c values, the evaluation of HDL quality might be an improved tool for identifying subjects at increased risk of cardiovascular events. Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is involved in the onset of cardiovascular disease and responsible for HDL antioxidant function. The aim of the present study was to investigate the effect of EFV on the circulating activity of PON-1 in HIV-infected patients. METHODS: The patients included were adults with a documented HIV-1 infection, nontreated or treated with antiretroviral regimens including EFV 600 mg once daily as first therapeutic regimen for at least 3 months. The influence of treatment with EFV, HDL-c and CD4 cell count on PON-1 activity was analysed. RESULTS: HIV-infected White patients treated with EFV had higher PON-1 activity [77.35 U l(-1) (65.66, 89.04)] (P < 0.05) and higher PON-1 activity : HDL-c ratio [1.88 (1.49, 2.28)] (P < 0.01) than untreated patients. PON-1 activity was higher in Black patients (P < 0.001) and in patients with a CD4 cell count >500 cells ml(-1) (P= 0.0120). CONCLUSIONS: EFV-based antiretroviral regimens are associated with HDL particles with a better antioxidant function, i.e. with a higher PON-1 activity. The PON-1 activity of Black patients is higher than that found in Whites regardless of treatment. Ethnicity should be taken into consideration when studying drug effects on PON-1 activity.